diff --git a/routes/chat.py b/routes/chat.py
index 40d0f82..6ecb5e5 100644
--- a/routes/chat.py
+++ b/routes/chat.py
@@ -191,8 +191,9 @@ async def enhanced_generate_stream_response(
                 if all(task.done() for task in [preamble_task_handle, agent_task_handle]):
                     # 所有任务都完成了，退出循环
                     break
-                # 发送 SSE 心跳注释保持连接活跃，防止 nginx/客户端超时断开
-                yield ": heartbeat\n\n"
+                # 发送空内容心跳包保持连接活跃，防止 nginx/客户端超时断开
+                heartbeat_chunk = create_stream_chunk(f"chatcmpl-heartbeat", config.model_name, "")
+                yield f"data: {json.dumps(heartbeat_chunk, ensure_ascii=False)}\n\n"
                 continue
 
         # 发送结束标记