diff --git a/src/daemon/spawner.py b/src/daemon/spawner.py
index 27d35ff..a12a54b 100644
--- a/src/daemon/spawner.py
+++ b/src/daemon/spawner.py
@@ -976,4 +976,9 @@ curl -X POST http://{api_host}:{api_port}/api/projects/{project_id}/tasks/{task_
     def cleanup_session(self, session_id: str) -> None:
         """清理 session"""
         if session_id in self._sessions:
+            session = self._sessions[session_id]
+            task_id = session.get("task_id")
             del self._sessions[session_id]
+            # 清理 B2 compact 等待计数器
+            if task_id and task_id in self._compact_waits:
+                del self._compact_waits[task_id]