diff --git a/im.go b/im.go
index 40970c0..502bf4b 100644
--- a/im.go
+++ b/im.go
@@ -8,102 +8,108 @@
 package im
 
 import (
-    "github.com/dobyte/tencent-im/account"
-    "github.com/dobyte/tencent-im/group"
-    "github.com/dobyte/tencent-im/internal/core"
-    "github.com/dobyte/tencent-im/mute"
-    "github.com/dobyte/tencent-im/operation"
-    "github.com/dobyte/tencent-im/private"
-    "github.com/dobyte/tencent-im/profile"
-    "github.com/dobyte/tencent-im/push"
-    "github.com/dobyte/tencent-im/sns"
+	"github.com/dobyte/tencent-im/account"
+	"github.com/dobyte/tencent-im/group"
+	"github.com/dobyte/tencent-im/internal/core"
+	"github.com/dobyte/tencent-im/internal/sign"
+	"github.com/dobyte/tencent-im/mute"
+	"github.com/dobyte/tencent-im/operation"
+	"github.com/dobyte/tencent-im/private"
+	"github.com/dobyte/tencent-im/profile"
+	"github.com/dobyte/tencent-im/push"
+	"github.com/dobyte/tencent-im/sns"
 )
 
 type Error = core.Error
 
 type (
-    IM interface {
-        // SNS 获取关系链管理接口
-        SNS() sns.API
-        // Mute 获取全局禁言管理接口
-        Mute() mute.API
-        // Push 获取全员推送接口
-        Push() push.API
-        // Group 获取群组管理接口
-        Group() group.API
-        // Account 获取账号管理接口
-        Account() account.API
-        // Profile 获取资料管理接口
-        Profile() profile.API
-        // Private 获取私聊消息接口
-        Private() private.API
-        // Operation 获取运营管理接口
-        Operation() operation.API
-    }
-    
-    Options struct {
-        AppId     int    // 应用 SDKAppID，可在即时通信 IM 控制台 的应用卡片中获取。
-        AppSecret string // 密钥信息，可在即时通信 IM 控制台 的应用详情页面中获取，具体操作请参见 获取密钥
-        UserId    string // 用户ID
-    }
-    
-    im struct {
-        client    core.Client
-        appId     int
-        appSecret string
-    }
+	IM interface {
+		// GetUserSig 获取UserSig签名
+		GetUserSig() string
+		// SNS 获取关系链管理接口
+		SNS() sns.API
+		// Mute 获取全局禁言管理接口
+		Mute() mute.API
+		// Push 获取全员推送接口
+		Push() push.API
+		// Group 获取群组管理接口
+		Group() group.API
+		// Account 获取账号管理接口
+		Account() account.API
+		// Profile 获取资料管理接口
+		Profile() profile.API
+		// Private 获取私聊消息接口
+		Private() private.API
+		// Operation 获取运营管理接口
+		Operation() operation.API
+	}
+	
+	Options struct {
+		AppId     int    // 应用SDKAppID，可在即时通信 IM 控制台 的应用卡片中获取。
+		AppSecret string // 密钥信息，可在即时通信 IM 控制台 的应用详情页面中获取，具体操作请参见 获取密钥
+		UserId    string // 用户ID
+		Expire    int    // UserSig过期时间
+	}
+	
+	im struct {
+		opt    Options
+		client core.Client
+	}
 )
 
-// NewIM create a im instance.
 func NewIM(opt Options) IM {
-    return &im{
-        appId: opt.AppId,
-        client: core.NewClient(core.Options{
-            AppId:     opt.AppId,
-            AppSecret: opt.AppSecret,
-            UserId:    opt.UserId,
-        }),
-    }
+	return &im{opt: opt, client: core.NewClient(core.Options{
+		AppId:     opt.AppId,
+		AppSecret: opt.AppSecret,
+		UserId:    opt.UserId,
+		Expire:    opt.Expire,
+	})}
+}
+
+// GetUserSig 获取UserSig签名
+func (i *im) GetUserSig() string {
+	userSig, _ := sign.GenUserSig(i.opt.AppId, i.opt.AppSecret, i.opt.UserId, i.opt.Expire)
+	return userSig
 }
 
 // SNS 获取关系链管理接口
 func (i *im) SNS() sns.API {
-    return sns.NewAPI(i.client)
+	return sns.NewAPI(i.client)
 }
 
 // Mute 获取全局禁言管理接口
 func (i *im) Mute() mute.API {
-    return mute.NewAPI(i.client)
+	return mute.NewAPI(i.client)
 }
 
 // Push 获取全员推送接口
 func (i *im) Push() push.API {
-    return push.NewAPI(i.client)
+	return push.NewAPI(i.client)
 }
 
 // Group 获取群组管理接口
 func (i *im) Group() group.API {
-    return group.NewAPI(i.client)
+	return group.NewAPI(i.client)
 }
 
 // Account 获取账号管理接口
 func (i *im) Account() account.API {
-    return account.NewAPI(i.client)
+	return account.NewAPI(i.client)
 }
 
 // Profile 获取资料管理接口
 func (i *im) Profile() profile.API {
-    return profile.NewAPI(i.client)
+	return profile.NewAPI(i.client)
 }
 
 // Private 获取私聊消息接口
 func (i *im) Private() private.API {
-    return private.NewAPI(i.client)
+	return private.NewAPI(i.client)
 }
 
 // Operation 获取运营管理接口
 func (i *im) Operation() operation.API {
-    return operation.NewAPI(i.client)
+	return operation.NewAPI(i.client)
 }
 
 func (i *im) Callback() {
diff --git a/im_test.go b/im_test.go
index c06cdc1..9457500 100644
--- a/im_test.go
+++ b/im_test.go
@@ -13,7 +13,7 @@ import (
 	"strconv"
 	"testing"
 	"time"
-
+	
 	"github.com/dobyte/tencent-im"
 	"github.com/dobyte/tencent-im/account"
 	"github.com/dobyte/tencent-im/group"
@@ -53,6 +53,17 @@ func NewIM() im.IM {
 //     })
 // }
 
+// GetUserSig 获取UserSig签名
+func TestIm_GetUserSig(t *testing.T) {
+	tim := NewIM()
+	
+	for i := 0; i < 1000; i++ {
+		tim.GetUserSig()
+	}
+	
+	t.Log("Success")
+}
+
 // 导入单个账号
 func TestIm_Account_ImportAccount(t *testing.T) {
 	if err := NewIM().Account().ImportAccount(account.Info{
@@ -63,7 +74,7 @@ func TestIm_Account_ImportAccount(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log("Success")
 }
 
@@ -84,7 +95,7 @@ func TestIm_Account_ImportAccounts(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(failedAccounts)
 }
 
@@ -95,7 +106,7 @@ func TestIm_Account_DeleteAccount(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log("Success")
 }
 
@@ -116,7 +127,7 @@ func TestIm_Account_DeleteAccounts(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(deleteResults)
 }
 
@@ -137,7 +148,7 @@ func TestIm_Account_CheckAccounts(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(checkResults)
 }
 
@@ -147,7 +158,7 @@ func TestIm_Account_KickAccount(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log("Success")
 }
 
@@ -158,7 +169,7 @@ func TestIm_Account_QueryAccountOnlineStatus(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(ret)
 }
 
@@ -172,7 +183,7 @@ func TestIm_Account_QueryAccountsOnlineStatus(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(resp.Results)
 	t.Log(resp.Errors)
 }
@@ -193,13 +204,13 @@ func TestIm_Push_Push(t *testing.T) {
 	})
 	message.OfflinePush().SetAndroidExtAsHuaweiIntentParam(push.HuaweiIntentParamIntent)
 	message.OfflinePush().SetApnsBadgeMode(push.BadgeModeNormal)
-
+	
 	taskId, err := NewIM().Push().PushMessage(message)
 	if err != nil {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(taskId)
 }
 
@@ -212,7 +223,7 @@ func TestIm_Push_SetAttrNames(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log("Success")
 }
 
@@ -223,7 +234,7 @@ func TestIm_Push_GetAttrNames(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(ret)
 }
 
@@ -234,7 +245,7 @@ func TestIm_Push_GetUserAttrs(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(ret)
 }
 
@@ -250,7 +261,7 @@ func TestIm_Push_SetUserAttrs(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log("Success")
 }
 
@@ -263,7 +274,7 @@ func TestIm_Push_DeleteUserAttrs(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log("Success")
 }
 
@@ -274,7 +285,7 @@ func TestIm_Push_GetUserTags(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(ret)
 }
 
@@ -287,7 +298,7 @@ func TestIm_Push_AddUserTags(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log("Success")
 }
 
@@ -300,7 +311,7 @@ func TestIm_Push_DeleteUserTags(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log("Success")
 }
 
@@ -311,7 +322,7 @@ func TestIm_Push_DeleteUserAllTags(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log("Success")
 }
 
@@ -324,12 +335,12 @@ func TestIm_Profile_SetProfile(t *testing.T) {
 	p.SetLocation(1, 23, 27465, 92)
 	// p.SetLocation(1, 23, 2, 92)
 	p.SetLanguage(20)
-
+	
 	if err := NewIM().Profile().SetProfile(p); err != nil {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log("Success")
 }
 
@@ -348,7 +359,7 @@ func TestIm_Profile_GetProfile(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	for _, p := range profiles {
 		t.Log(p.GetUserId())
 		t.Log(p.GetNickname())
@@ -366,7 +377,7 @@ func TestIm_Operation_GetOperationData(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(data)
 }
 
@@ -377,7 +388,7 @@ func TestIm_Operation_GetHistoryData(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(files)
 }
 
@@ -388,7 +399,7 @@ func TestIm_Operation_GetIpList(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(ips)
 }
 
@@ -400,7 +411,7 @@ func TestIm_Mute_SetNoSpeaking(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log("Success")
 }
 
@@ -411,7 +422,7 @@ func TestIm_Mute_GetNoSpeaking(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(privateMuteTime)
 	t.Log(groupMuteTime)
 }
@@ -419,7 +430,7 @@ func TestIm_Mute_GetNoSpeaking(t *testing.T) {
 // 添加好友
 func TestIm_SNS_AddFriends(t *testing.T) {
 	friends := make([]*sns.Friend, 0)
-
+	
 	var friend *sns.Friend
 	var userIds []string
 	var userId string
@@ -431,28 +442,28 @@ func TestIm_SNS_AddFriends(t *testing.T) {
 		friends = append(friends, friend)
 		userIds = append(userIds, userId)
 	}
-
+	
 	failUserIds, err := NewIM().Account().ImportAccounts(userIds...)
 	if err != nil {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(failUserIds)
-
+	
 	results, err := NewIM().SNS().AddFriends("assistant", friends, true, false)
 	if err != nil {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(results)
 }
 
 // 导入好友
 func TestIm_SNS_ImportFriends(t *testing.T) {
 	friends := make([]*sns.Friend, 0)
-
+	
 	var friend *sns.Friend
 	var userIds []string
 	var userId string
@@ -470,28 +481,28 @@ func TestIm_SNS_ImportFriends(t *testing.T) {
 		friends = append(friends, friend)
 		userIds = append(userIds, userId)
 	}
-
+	
 	failUserIds, err := NewIM().Account().ImportAccounts(userIds...)
 	if err != nil {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(failUserIds)
-
+	
 	results, err := NewIM().SNS().ImportFriends("assistant", friends)
 	if err != nil {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(results)
 }
 
 // 更新好友
 func TestIm_SNS_UpdateFriends(t *testing.T) {
 	friends := make([]*sns.Friend, 0)
-
+	
 	var friend *sns.Friend
 	var userIds []string
 	var userId string
@@ -509,21 +520,21 @@ func TestIm_SNS_UpdateFriends(t *testing.T) {
 		friends = append(friends, friend)
 		userIds = append(userIds, userId)
 	}
-
+	
 	failUserIds, err := NewIM().Account().ImportAccounts(userIds...)
 	if err != nil {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(failUserIds)
-
+	
 	results, err := NewIM().SNS().UpdateFriends("assistant", friends)
 	if err != nil {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(results)
 }
 
@@ -535,13 +546,13 @@ func TestIm_SNS_DeleteFriends(t *testing.T) {
 		userId = "test" + strconv.Itoa(i)
 		userIds = append(userIds, userId)
 	}
-
+	
 	results, err := NewIM().SNS().DeleteFriends("assistant", userIds, false)
 	if err != nil {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(results)
 }
 
@@ -552,7 +563,7 @@ func TestIm_SNS_DeleteAllFriends(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log("Success")
 }
 
@@ -564,13 +575,13 @@ func TestIm_SNS_CheckFriends(t *testing.T) {
 		userId = "test" + strconv.Itoa(i)
 		userIds = append(userIds, userId)
 	}
-
+	
 	results, err := NewIM().SNS().CheckFriends("assistant", userIds, sns.CheckTypeSingle)
 	if err != nil {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(results)
 }
 
@@ -582,7 +593,7 @@ func TestIm_SNS_GetFriends(t *testing.T) {
 		userId = "test" + strconv.Itoa(i)
 		userIds = append(userIds, userId)
 	}
-
+	
 	friends, err := NewIM().SNS().GetFriends("assistant", userIds, []string{
 		sns.FriendAttrAddSource,
 		sns.FriendAttrRemark,
@@ -597,7 +608,7 @@ func TestIm_SNS_GetFriends(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	// 第一种获取方式
 	for _, friend := range friends {
 		if friend.IsValid() {
@@ -611,7 +622,7 @@ func TestIm_SNS_GetFriends(t *testing.T) {
 			fmt.Println()
 		}
 	}
-
+	
 	// 第二种获取方式
 	for _, friend := range friends {
 		if err := friend.GetError(); err != nil {
@@ -639,18 +650,18 @@ func TestIm_SNS_FetchFriends(t *testing.T) {
 		standardSequence = 0
 		customSequence   = 0
 	)
-
+	
 	for ret == nil || !ret.IsOver {
 		ret, err = s.FetchFriends("assistant", startIndex, standardSequence, customSequence)
 		if err != nil {
 			t.Error(err)
 			return
 		}
-
+		
 		startIndex = ret.NextStartIndex
 		standardSequence = ret.StandardSequence
 		customSequence = ret.CustomSequence
-
+		
 		t.Log("下一个开始点：", ret.NextStartIndex)
 		t.Log("是否拉取完毕：", ret.IsOver)
 		t.Log("标准排序：", ret.StandardSequence)
@@ -681,13 +692,13 @@ func TestIm_SNS_AddBlacklist(t *testing.T) {
 		userId = "test" + strconv.Itoa(i)
 		userIds = append(userIds, userId)
 	}
-
+	
 	results, err := NewIM().SNS().AddBlacklist("assistant", userIds)
 	if err != nil {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(results)
 }
 
@@ -699,13 +710,13 @@ func TestIm_SNS_DeleteBlacklist(t *testing.T) {
 		userId = "test" + strconv.Itoa(i)
 		userIds = append(userIds, userId)
 	}
-
+	
 	results, err := NewIM().SNS().DeleteBlacklist("assistant", userIds)
 	if err != nil {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(results)
 }
 
@@ -719,17 +730,17 @@ func TestIm_SNS_FetchBlacklist(t *testing.T) {
 		maxLimited       = 2
 		standardSequence = 0
 	)
-
+	
 	for ret == nil || !ret.IsOver {
 		ret, err = s.FetchBlacklist("assistant", startIndex, maxLimited, standardSequence)
 		if err != nil {
 			t.Error(err)
 			return
 		}
-
+		
 		startIndex = ret.NextStartIndex
 		standardSequence = ret.StandardSequence
-
+		
 		t.Log("下一个开始点：", startIndex)
 		t.Log("标准排序：", standardSequence)
 		t.Log("黑名单列表：")
@@ -750,13 +761,13 @@ func TestIm_SNS_CheckBlacklist(t *testing.T) {
 		userId = "test" + strconv.Itoa(i)
 		userIds = append(userIds, userId)
 	}
-
+	
 	results, err := NewIM().SNS().CheckBlacklist("assistant", userIds, sns.BlacklistCheckTypeSingle)
 	if err != nil {
 		t.Error(err)
 		return
 	}
-
+	
 	for _, result := range results {
 		if result.ResultCode == 0 {
 			t.Log(result.UserId)
@@ -783,7 +794,7 @@ func TestIm_SNS_AddGroups(t *testing.T) {
 		userId = "test" + strconv.Itoa(i)
 		userIds = append(userIds, userId)
 	}
-
+	
 	_, results, err := NewIM().SNS().AddGroups("assistant", []string{
 		"测试3",
 		"测试4",
@@ -792,7 +803,7 @@ func TestIm_SNS_AddGroups(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(results)
 }
 
@@ -806,7 +817,7 @@ func TestIm_SNS_DeleteGroups(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log("Success")
 }
 
@@ -821,13 +832,13 @@ func TestIm_SNS_GetGroups(t *testing.T) {
 		}
 		results []sns.GroupResult
 	)
-
+	
 	lastSequence, results, err = NewIM().SNS().GetGroups("assistant", lastSequence, true, groupName)
 	if err != nil {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(results)
 }
 
@@ -849,13 +860,13 @@ func TestIm_Private_SendMessage(t *testing.T) {
 	})
 	message.OfflinePush().SetAndroidExtAsHuaweiIntentParam(private.HuaweiIntentParamIntent)
 	message.OfflinePush().SetApnsBadgeMode(private.BadgeModeNormal)
-
+	
 	ret, err := NewIM().Private().SendMessage(message)
 	if err != nil {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(ret.MsgKey)
 	t.Log(ret.MsgTime)
 }
@@ -868,13 +879,13 @@ func TestIm_Private_SendMessages(t *testing.T) {
 	message.SetContent(private.MsgTextContent{
 		Text: "Hello world",
 	})
-
+	
 	ret, err := NewIM().Private().SendMessages(message)
 	if err != nil {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(ret.MsgKey)
 	t.Log(ret.Errors)
 }
@@ -889,13 +900,13 @@ func TestIm_Private_ImportMessage(t *testing.T) {
 	message.SetContent(private.MsgTextContent{
 		Text: "Hello world",
 	})
-
+	
 	err := NewIM().Private().ImportMessage(message)
 	if err != nil {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log("Success")
 }
 
@@ -913,19 +924,19 @@ func TestIm_Private_FetchMessages(t *testing.T) {
 			MaxTime:    time.Now().Unix(),
 		}
 	)
-
+	
 	for ret == nil || !ret.IsOver {
 		ret, err = p.FetchMessages(arg)
 		if err != nil {
 			t.Error(err)
 			return
 		}
-
+		
 		if !ret.IsOver {
 			arg.LastMsgKey = ret.LastMsgKey
 			arg.MaxTime = ret.LastMsgTime
 		}
-
+		
 		t.Log(ret.IsOver)
 		t.Log(ret.LastMsgKey)
 		t.Log(ret.LastMsgTime)
@@ -955,7 +966,7 @@ func TestIm_Private_PullMessages(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log("Success")
 }
 
@@ -966,7 +977,7 @@ func TestIm_Private_RevokeMessage(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log("Success")
 }
 
@@ -977,7 +988,7 @@ func TestIm_Private_SetMessageRead(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log("Success")
 }
 
@@ -991,7 +1002,7 @@ func TestIm_Private_GetUnreadMessageNum(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(ret.Total)
 	t.Log(ret.UnreadList)
 	t.Log(ret.ErrorList)
@@ -1007,20 +1018,20 @@ func TestIm_Group_CreateGroup(t *testing.T) {
 	// g.SetId("test_group1")
 	g.SetIntroduction("这是一个测试群")
 	g.SetNotification("这是一个测试群公告")
-
+	
 	for i := 1; i < 10; i++ {
 		member := group.NewMember()
 		member.SetUserId("test" + strconv.Itoa(i))
 		member.SetJoinTime(time.Now())
 		g.AddMembers(member)
 	}
-
+	
 	groupId, err := NewIM().Group().CreateGroup(g)
 	if err != nil {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(groupId)
 }
 
@@ -1031,7 +1042,7 @@ func TestIm_Group_DestroyGroup(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log("Success")
 }
 
@@ -1042,7 +1053,7 @@ func TestIm_Group_GetGroup(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	if g != nil {
 		t.Log(g.GetId())
 		t.Log(g.GetName())
@@ -1061,7 +1072,7 @@ func TestIm_Group_GetGroups(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	for _, g := range groups {
 		if err = g.GetError(); err != nil {
 			t.Error(err)
@@ -1085,7 +1096,7 @@ func TestIm_Group_AddGroupMembers(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(results)
 }
 
@@ -1100,7 +1111,7 @@ func TestIm_Group_DeleteGroupMembers(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log("Success")
 }
 
@@ -1111,7 +1122,7 @@ func TestIm_Group_ChangeGroupOwner(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log("Success")
 }
 
@@ -1125,13 +1136,13 @@ func TestIm_Group_UpdateGroup(t *testing.T) {
 	g.SetId("test_group1")
 	g.SetIntroduction("这是一个测试群")
 	g.SetNotification("这是一个测试群公告")
-
+	
 	err := NewIM().Group().UpdateGroup(g)
 	if err != nil {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log("Success")
 }
 
@@ -1146,7 +1157,7 @@ func TestIm_Group_GetRolesInGroup(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(ret)
 }
 
@@ -1157,10 +1168,10 @@ func TestIm_Group_FetchGroupMembers(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(ret.HasMore)
 	t.Log(ret.Total)
-
+	
 	for _, member := range ret.List {
 		t.Log(member.GetUserId())
 	}
@@ -1173,7 +1184,7 @@ func TestIm_Group_FetchGroupIds(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(ret.Total)
 	t.Log(ret.Next)
 	t.Log(ret.HasMore)
@@ -1187,11 +1198,11 @@ func TestIm_Group_FetchGroups(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(ret.Total)
 	t.Log(ret.Next)
 	t.Log(ret.HasMore)
-
+	
 	for _, g := range ret.List {
 		t.Log(g.GetId())
 		t.Log(g.GetOwner())
@@ -1205,13 +1216,13 @@ func TestIm_Group_UpdateGroupMember(t *testing.T) {
 	member.SetRole("Admin")
 	member.SetNameCard("这是一个测试名片信息")
 	member.SetMsgFlag(group.MsgFlagAcceptAndNotify)
-
+	
 	err := NewIM().Group().UpdateMember("test_group1", member)
 	if err != nil {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log("Success")
 }
 
@@ -1228,7 +1239,7 @@ func TestIm_Group_FetchMemberGroups(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(ret.Total)
 	t.Log(ret.HasMore)
 	t.Log(ret.List)
@@ -1243,7 +1254,7 @@ func TestIm_Group_ForbidSendMessage(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log("Success")
 }
 
@@ -1257,7 +1268,7 @@ func TestIm_Group_AllowSendMessage(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log("Success")
 }
 
@@ -1268,7 +1279,7 @@ func TestIm_Group_GetShuttedUpMembers(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(shuttedUps)
 }
 
@@ -1279,7 +1290,7 @@ func TestIm_Group_RevokeMessage(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log("Success")
 }
 
@@ -1290,7 +1301,7 @@ func TestIm_Group_RevokeMessages(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(results)
 }
 
@@ -1301,7 +1312,7 @@ func TestIm_Group_SetMemberUnreadMsgNum(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log("Success")
 }
 
@@ -1312,7 +1323,7 @@ func TestIm_Group_RevokeMemberMessages(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log("Success")
 }
 
@@ -1337,13 +1348,13 @@ func TestIm_Group_SendMessage(t *testing.T) {
 	message.AtAllMembers()
 	message.AtMembers(test2)
 	message.ClearAtMembers()
-
+	
 	ret, err := NewIM().Group().SendMessage("test_group1", message)
 	if err != nil {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(ret.MsgSeq)
 	t.Log(ret.MsgTime)
 }
@@ -1355,7 +1366,7 @@ func TestIm_Group_SendNotification(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log("Success")
 }
 
@@ -1368,13 +1379,13 @@ func TestIm_Group_ImportGroup(t *testing.T) {
 	g.SetAvatar("http://www.baidu.com")
 	g.SetIntroduction("这是一个测试群")
 	g.SetNotification("这是一个测试群公告")
-
+	
 	groupId, err := NewIM().Group().ImportGroup(g)
 	if err != nil {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(groupId)
 }
 
@@ -1387,13 +1398,13 @@ func TestIm_Group_ImportMessages(t *testing.T) {
 	message.SetContent(private.MsgTextContent{
 		Text: "Hello world",
 	})
-
+	
 	results, err := NewIM().Group().ImportMessages("test_group1", message)
 	if err != nil {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(results)
 }
 
@@ -1408,13 +1419,13 @@ func TestIm_Group_ImportMembers(t *testing.T) {
 		member.SetJoinTime(time.Now())
 		members = append(members, member)
 	}
-
+	
 	results, err := NewIM().Group().ImportMembers("@TGS#25J4AWNHA", members...)
 	if err != nil {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(results)
 }
 
@@ -1425,6 +1436,6 @@ func TestIm_Group_FetchMessages(t *testing.T) {
 		t.Error(err)
 		return
 	}
-
+	
 	t.Log(ret)
 }
diff --git a/internal/core/client.go b/internal/core/client.go
index d0c8823..113b465 100644
--- a/internal/core/client.go
+++ b/internal/core/client.go
@@ -8,140 +8,141 @@
 package core
 
 import (
-    "encoding/json"
-    "errors"
-    "fmt"
-    "math/rand"
-    "time"
-    
-    "github.com/dobyte/http"
-    
-    "github.com/dobyte/tencent-im/internal/enum"
-    "github.com/dobyte/tencent-im/internal/sign"
-    "github.com/dobyte/tencent-im/internal/types"
+	"errors"
+	"fmt"
+	"math/rand"
+	"time"
+	
+	"github.com/dobyte/http"
+	
+	"github.com/dobyte/tencent-im/internal/enum"
+	"github.com/dobyte/tencent-im/internal/sign"
+	"github.com/dobyte/tencent-im/internal/types"
 )
 
 const (
-    defaultBaseUrl     = "https://console.tim.qq.com"
-    defaultVersion     = "v4"
-    defaultTimeout     = 5
-    defaultContentType = "json"
-    defaultExpire      = 60
+	defaultBaseUrl     = "https://console.tim.qq.com"
+	defaultVersion     = "v4"
+	defaultContentType = "json"
+	defaultExpire      = 3600
 )
 
 var invalidResponse = errors.New("invalid response")
 
 type Client interface {
-    // Get send an http request use get method.
-    Get(serviceName string, command string, data interface{}, resp interface{}) error
-    // Post send an http request use post method.
-    Post(serviceName string, command string, data interface{}, resp interface{}) error
-    // Put send an http request use put method.
-    Put(serviceName string, command string, data interface{}, resp interface{}) error
-    // Patch send an http request use patch method.
-    Patch(serviceName string, command string, data interface{}, resp interface{}) error
-    // Delete send an http request use patch method.
-    Delete(serviceName string, command string, data interface{}, resp interface{}) error
+	// Get send an http request use get method.
+	Get(serviceName string, command string, data interface{}, resp interface{}) error
+	// Post send an http request use post method.
+	Post(serviceName string, command string, data interface{}, resp interface{}) error
+	// Put send an http request use put method.
+	Put(serviceName string, command string, data interface{}, resp interface{}) error
+	// Patch send an http request use patch method.
+	Patch(serviceName string, command string, data interface{}, resp interface{}) error
+	// Delete send an http request use patch method.
+	Delete(serviceName string, command string, data interface{}, resp interface{}) error
 }
 
 type client struct {
-    client    *http.Client
-    appId     int
-    appSecret string
-    userId    string
+	client          *http.Client
+	opt             Options
+	userSig         string
+	userSigExpireAt int64
 }
 
 type Options struct {
-    AppId     int    // 应用SDKAppID，可在即时通信 IM 控制台 的应用卡片中获取。
-    AppSecret string // 密钥信息，可在即时通信 IM 控制台 的应用详情页面中获取，具体操作请参见 获取密钥
-    UserId    string // 用户ID
+	AppId     int    // 应用SDKAppID，可在即时通信 IM 控制台 的应用卡片中获取。
+	AppSecret string // 密钥信息，可在即时通信 IM 控制台 的应用详情页面中获取，具体操作请参见 获取密钥
+	UserId    string // 用户ID
+	Expire    int    // UserSig过期时间
 }
 
 func NewClient(opt Options) Client {
-    rand.Seed(time.Now().UnixNano())
-    c := new(client)
-    c.appId = opt.AppId
-    c.appSecret = opt.AppSecret
-    c.userId = opt.UserId
-    c.client = http.NewClient()
-    c.client.SetContentType(http.ContentTypeJson)
-    // c.client.SetTimeout(defaultTimeout)
-    c.client.SetBaseUrl(defaultBaseUrl)
-    
-    return c
+	rand.Seed(time.Now().UnixNano())
+	c := new(client)
+	c.opt = opt
+	c.client = http.NewClient()
+	c.client.SetContentType(http.ContentTypeJson)
+	c.client.SetBaseUrl(defaultBaseUrl)
+	
+	return c
 }
 
 // Get send an http request use get method.
 func (c *client) Get(serviceName string, command string, data interface{}, resp interface{}) error {
-    return c.request(http.MethodGet, serviceName, command, data, resp)
+	return c.request(http.MethodGet, serviceName, command, data, resp)
 }
 
 // Post send an http request use post method.
 func (c *client) Post(serviceName string, command string, data interface{}, resp interface{}) error {
-    return c.request(http.MethodPost, serviceName, command, data, resp)
+	return c.request(http.MethodPost, serviceName, command, data, resp)
 }
 
 // Put send an http request use put method.
 func (c *client) Put(serviceName string, command string, data interface{}, resp interface{}) error {
-    return c.request(http.MethodPut, serviceName, command, data, resp)
+	return c.request(http.MethodPut, serviceName, command, data, resp)
 }
 
 // Patch send an http request use patch method.
 func (c *client) Patch(serviceName string, command string, data interface{}, resp interface{}) error {
-    return c.request(http.MethodPatch, serviceName, command, data, resp)
+	return c.request(http.MethodPatch, serviceName, command, data, resp)
 }
 
 // Delete send an http request use patch method.
 func (c *client) Delete(serviceName string, command string, data interface{}, resp interface{}) error {
-    return c.request(http.MethodDelete, serviceName, command, data, resp)
+	return c.request(http.MethodDelete, serviceName, command, data, resp)
 }
 
 // request send an http request.
 func (c *client) request(method, serviceName, command string, data, resp interface{}) error {
-    res, err := c.client.Request(method, c.buildUrl(serviceName, command), data)
-    if err != nil {
-        return err
-    }
-    js, _ := json.Marshal(data)
-    fmt.Println(string(js))
-    fmt.Println(res.ReadString())
-    if err = res.Scan(resp); err != nil {
-        return err
-    }
-    
-    if r, ok := resp.(types.ActionBaseRespInterface); ok {
-        if r.GetActionStatus() == enum.FailActionStatus {
-            return NewError(r.GetErrorCode(), r.GetErrorInfo())
-        }
-        
-        if r.GetErrorCode() != enum.SuccessCode {
-            return NewError(r.GetErrorCode(), r.GetErrorInfo())
-        }
-    } else if r, ok := resp.(types.BaseRespInterface); ok {
-        if r.GetErrorCode() != enum.SuccessCode {
-            return NewError(r.GetErrorCode(), r.GetErrorInfo())
-        }
-    } else {
-        return invalidResponse
-    }
-    
-    return nil
+	res, err := c.client.Request(method, c.buildUrl(serviceName, command), data)
+	if err != nil {
+		return err
+	}
+
+	if err = res.Scan(resp); err != nil {
+		return err
+	}
+	
+	if r, ok := resp.(types.ActionBaseRespInterface); ok {
+		if r.GetActionStatus() == enum.FailActionStatus {
+			return NewError(r.GetErrorCode(), r.GetErrorInfo())
+		}
+		
+		if r.GetErrorCode() != enum.SuccessCode {
+			return NewError(r.GetErrorCode(), r.GetErrorInfo())
+		}
+	} else if r, ok := resp.(types.BaseRespInterface); ok {
+		if r.GetErrorCode() != enum.SuccessCode {
+			return NewError(r.GetErrorCode(), r.GetErrorInfo())
+		}
+	} else {
+		return invalidResponse
+	}
+	
+	return nil
 }
 
 // buildUrl build a request url.
 func (c *client) buildUrl(serviceName string, command string) string {
-    random := rand.Int31()
-    userSign, _ := sign.GenUserSign(c.appId, c.appSecret, c.userId, defaultExpire)
-    url := fmt.Sprintf("/%s/%s/%s?sdkappid=%d&identifier=%s&usersig=%s&random=%d&contenttype=%s",
-        defaultVersion,
-        serviceName,
-        command,
-        c.appId,
-        c.userId,
-        userSign,
-        random,
-        defaultContentType,
-    )
-    
-    return url
+	format := "/%s/%s/%s?sdkappid=%d&identifier=%s&usersig=%s&random=%d&contenttype=%s"
+	random := rand.Int31()
+	userSig := c.getUserSig()
+	return fmt.Sprintf(format, defaultVersion, serviceName, command, c.opt.AppId, c.opt.UserId, userSig, random, defaultContentType)
 }
+
+// getUserSig get a userSig
+func (c *client) getUserSig() string {
+	now := time.Now()
+	expire := c.opt.Expire
+	
+	if expire <= 0 {
+		expire = defaultExpire
+	}
+	
+	if c.userSig == "" || c.userSigExpireAt <= now.Unix() {
+		c.userSig, _ = sign.GenUserSig(c.opt.AppId, c.opt.AppSecret, c.opt.UserId, expire)
+		c.userSigExpireAt = now.Add(time.Duration(expire) * time.Second).Unix()
+	}
+	
+	return c.userSig
+}
\ No newline at end of file
diff --git a/internal/sign/sign.go b/internal/sign/sign.go
index c9a8eae..f259548 100644
--- a/internal/sign/sign.go
+++ b/internal/sign/sign.go
@@ -18,23 +18,21 @@ import (
     "time"
 )
 
-// GenUserSign gen a user sign.
-func GenUserSign(sdkAppId int, key string, userid string, expire int) (string, error) {
-    return genSign(sdkAppId, key, userid, expire, nil)
+// GenUserSig gen a user sign.
+func GenUserSig(sdkAppId int, key string, userid string, expire int) (string, error) {
+    return genUserSig(sdkAppId, key, userid, expire, nil)
 }
 
 // GenPrivateMapKey gen a private map.
 func GenPrivateMapKey(sdkAppId int, key string, userid string, expire int, roomId uint32, privilegeMap uint32) (string, error) {
     var userBuf []byte = genUserBuf(userid, sdkAppId, roomId, expire, privilegeMap, 0, "")
-    
-    return genSign(sdkAppId, key, userid, expire, userBuf)
+    return genUserSig(sdkAppId, key, userid, expire, userBuf)
 }
 
 // GenPrivateMapKeyWithRoomId gen a private map with room id.
 func GenPrivateMapKeyWithRoomId(sdkAppId int, key string, userid string, expire int, roomId string, privilegeMap uint32) (string, error) {
     var userBuf []byte = genUserBuf(userid, sdkAppId, 0, expire, privilegeMap, 0, roomId)
-    
-    return genSign(sdkAppId, key, userid, expire, userBuf)
+    return genUserSig(sdkAppId, key, userid, expire, userBuf)
 }
 
 // genUserBuf gen a user buffer.
@@ -148,8 +146,8 @@ func hmacSha256(sdkAppId int, key string, identifier string, currTime int64, exp
     return base64.StdEncoding.EncodeToString(h.Sum(nil))
 }
 
-// genSign gen a sign
-func genSign(sdkAppId int, key string, identifier string, expire int, userBuf []byte) (string, error) {
+// genUserSig gen a sign
+func genUserSig(sdkAppId int, key string, identifier string, expire int, userBuf []byte) (string, error) {
     currTime := time.Now().Unix()
     var sigDoc map[string]interface{}
     sigDoc = make(map[string]interface{})