diff --git a/deviceservice.cpp b/deviceservice.cpp
index 76ef88d..38ec1c7 100644
--- a/deviceservice.cpp
+++ b/deviceservice.cpp
@@ -143,7 +143,7 @@ quint8 DeviceService::keyDetection()
     }
 
     //记录上一行为及时间
-    if(flag != key.flag)
+    if(flag != None && flag != key.flag)
     {
         key.flag = flag;
         lastFlagTime = QTime::currentTime();