diff --git a/mpmaster/src/main/java/com/xypower/mpmaster/MpMasterService.java b/mpmaster/src/main/java/com/xypower/mpmaster/MpMasterService.java
index ab0e7e05..9586f8c8 100644
--- a/mpmaster/src/main/java/com/xypower/mpmaster/MpMasterService.java
+++ b/mpmaster/src/main/java/com/xypower/mpmaster/MpMasterService.java
@@ -610,8 +610,11 @@ public class MpMasterService extends Service {
 
         logger.warning("Start Mntn report: " + masterUrl + " MntnMode=" + (mMntnMode ? "1" : "0") + " QuickHB=" + (mQuickHbMode ? "1" : "0"));
 
-
-        AppMaster appMaster = new AppMaster(this, masterUrl, appConfig.cmdid, bundleWithMpApp);
+        String cmdid = appConfig.cmdid;
+        if (TextUtils.isEmpty(cmdid)) {
+            cmdid = getSerialNo();
+        }
+        AppMaster appMaster = new AppMaster(this, masterUrl, cmdid, bundleWithMpApp);
         appMaster.start(isCriticalTime());
         mMasterTimers++;
     }