diff --git a/app/api/ai_assist/service.py b/app/api/ai_assist/service.py
index 68f739b..afecc53 100644
--- a/app/api/ai_assist/service.py
+++ b/app/api/ai_assist/service.py
@@ -11,7 +11,7 @@ async def get_and_set_last_key(redis: Redis, word: str, user_id: str):
     print(last_word)
 
     # 如果上一次查的词和这次不同，就清空旧词的记录
-    if last_word and last_word.decode() != word:
+    if last_word and last_word != word:
         await clear_chat_history(redis, user_id, last_word.decode())
 
     # 更新当前词