diff --git a/DLPilot/src/app_gui.py b/DLPilot/src/app_gui.py
index c3f8f49..e8dc28e 100644
--- a/DLPilot/src/app_gui.py
+++ b/DLPilot/src/app_gui.py
@@ -34,7 +34,7 @@ BOLD = ('Microsoft YaHei UI', 13, 'bold')
 TITLE_FONT = ('Microsoft YaHei UI', 18, 'bold')
 
 APP_NAME = 'DLPilot'
-APP_VERSION = '0.3.2'
+APP_VERSION = '0.3.3'
 REPO_URL = 'https://gitea.hulk.wang/hulk/LT8619C_Debug_Tools'
 
 
diff --git a/DLPilot/src/dlpc_rs485.py b/DLPilot/src/dlpc_rs485.py
index 5b7d90f..e369f14 100644
--- a/DLPilot/src/dlpc_rs485.py
+++ b/DLPilot/src/dlpc_rs485.py
@@ -279,7 +279,12 @@ class DLPC485:
                             self.on_event(f'← {describe(fr)}  '
                                           f'[{fr.raw.hex(" ").upper()}]')
                 except OSError:
+                    try:
+                        self.ser.close()
+                    except Exception:
+                        pass
                     self.ser = None
+                    self._open_key = None     # 必须同步清除, 否则同参数重连被当作已打开而跳过
                     with self._lock:
                         self._target = None
                     self.on_status('串口丢失(设备拔出?), 请重新连接')