diff --git a/CHANGELOG.md b/CHANGELOG.md
index ec8fed9..f84ec6c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+# 4.0.0
+* iOS中的AliPay SDK升级到15.8.18
+* iOS的支付功能需要添加universal link
+
 # 3.3.2
 * Merge #155: 增加iOS privacy manifest
 
diff --git a/README.md b/README.md
index 8a9791e..66f0767 100644
--- a/README.md
+++ b/README.md
@@ -25,6 +25,8 @@ import 'package:tobias/tobias.dart' ;
 Tobias tobias = Tobias();
 tobias.pay(yourOrder);
 ```
+If you're working with iOS, please add and pass universal link. See [how to configure universal link](https://opendocs.alipay.com/open/0b9qzi).
+
 The result is map contains results from AliPay.The result also contains an external filed named `platform` which
 means the result is from `iOS` or `android`.
 Result sample:
diff --git a/README_CN.md b/README_CN.md
index 134fb47..3a1615e 100644
--- a/README_CN.md
+++ b/README_CN.md
@@ -26,7 +26,9 @@ import 'package:tobias/tobias.dart' ;
 Tobias tobias = Tobias();
 tobias.pay(yourOrder);
 ```
-   
+
+在iOS端, 你还需要配置并传入一个universal link. See [how to configure universal link](https://opendocs.alipay.com/open/0b9qzi).   
+
 返回值是一个包含支付宝支付结果的`map`。其中还包含了一个额外的 `platform`字段，
 它的值为 `iOS` 或 `android`。
 > 注意:Tobias 使用的是 pay_V2.
diff --git a/pubspec.yaml b/pubspec.yaml
index 4b9707f..8183274 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,6 +1,6 @@
 name: tobias
 description: A Flutter plugin for allowing users to authenticate or pay with native Android&iOS AliPay SDKs.
-version: 3.3.2
+version: 4.0.0
 homepage: https://github.com/OpenFlutter/tobias
 
 environment: