diff --git a/jobs/fetch_jianshu_lottery_win_records.py b/jobs/fetch_jianshu_lottery_win_records.py
index 02acdd2..70d70bd 100644
--- a/jobs/fetch_jianshu_lottery_win_records.py
+++ b/jobs/fetch_jianshu_lottery_win_records.py
@@ -5,7 +5,7 @@
 from jkit.jianshu_lottery import JianshuLottery, JianshuLotteryWinRecord
 from prefect import flow, get_run_logger
 from prefect.states import Completed, State
-from pymongo import DESCENDING
+from pymongo import ASCENDING, DESCENDING, IndexModel
 
 from utils.config_generators import generate_deployment_config, generate_flow_config
 from utils.db import DB
@@ -26,7 +26,7 @@ class UserInfoField(Field, **FIELD_OBJECT_CONFIG):
 
 
 class JianshuLotteryWinRecordDocument(Documemt, **DOCUMENT_OBJECT_CONFIG):
-    _id: PositiveInt  # type: ignore
+    record_id: PositiveInt
     time: datetime
     award_name: str
     user_info: UserInfoField
@@ -40,12 +40,12 @@ async def get_latest_stored_record_id() -> int:
     except StopAsyncIteration:
         return 0
 
-    return latest_data._id
+    return latest_data.record_id
 
 
 def process_item(item: JianshuLotteryWinRecord, /) -> JianshuLotteryWinRecordDocument:
     return JianshuLotteryWinRecordDocument(
-        _id=item.id,
+        record_id=item.id,
         time=item.time,
         award_name=item.award_name,
         user_info=UserInfoField(
@@ -62,6 +62,10 @@ def process_item(item: JianshuLotteryWinRecord, /) -> JianshuLotteryWinRecordDoc
     )
 )
 async def flow_func() -> State:
+    await COLLECTION.create_indexes(
+        [IndexModel([("recordId", ASCENDING)], unique=True)]
+    )
+
     logger = get_run_logger()
 
     stop_id = await get_latest_stored_record_id()