diff --git a/src/main/java/com/zhangshu/chat/demo/service/RoomCache.java b/src/main/java/com/zhangshu/chat/demo/service/RoomCache.java
index 097c052..b9f739f 100644
--- a/src/main/java/com/zhangshu/chat/demo/service/RoomCache.java
+++ b/src/main/java/com/zhangshu/chat/demo/service/RoomCache.java
@@ -54,7 +54,7 @@ public class RoomCache {
 
     public synchronized void addUser(String roomId, RoomUserVo user) {
         Room room = roomCache.get(roomId);
-        if (Objects.nonNull(room)) {
+        if (Objects.nonNull(room) && room.getUserList().stream().noneMatch(v -> v.getId().equals(user.getId()))) {
             room.getUserList().add(user);
         }
     }