diff --git a/src/ShimLib/ShimLib.c b/src/ShimLib/ShimLib.c
index d178d27..775d168 100644
--- a/src/ShimLib/ShimLib.c
+++ b/src/ShimLib/ShimLib.c
@@ -27,20 +27,26 @@ volatile int running = 1;
 volatile int progress = 0;
 volatile int status = READY;
 volatile int stop_flag = 0;
+volatile int empty = 0;
 char output_path[256] = {0};
 
 void ThreadFunc(void* args){
 	while (running){
-		WaitForSingleObject(e1, INFINITE);
-		status = SCANNING;
         stop_flag = 0;
-		progress = 0;
-		for (int i = 0; i <= 50; ++i) {
-			if (stop_flag > 0){
-				stop_flag = 0;
-				break;
-			}
+        progress = 0;
+		WaitForSingleObject(e1, INFINITE);
 
+        status = SCANNING;
+        Sleep(300);
+        if (empty)
+        {
+            GetPreviewData();
+        }
+		for (int i = 0; i <= 50; ++i) {
+            if (stop_flag > 0 || status != SCANNING){
+                stop_flag = 0;
+                break;
+            }
             if (i == 20){
                 progress = 139;
                 WaitForSingleObject(e2, INFINITE);
@@ -53,6 +59,10 @@ void ThreadFunc(void* args){
             }
             else{
                 progress = i *2;
+            }
+            if (stop_flag > 0 || status != SCANNING){
+                stop_flag = 0;
+                break;
             }
 			Sleep(300);
 		}
@@ -107,7 +117,8 @@ StatusInfo GetStatus() {
 }
 
 //result, 0 success, other false
-int SetScanInfo(const char* jsonString, int empty) {
+int SetScanInfo(const char* jsonString, int e) {
+    empty = e;
 	return 0;
 }
 
diff --git a/src/device/DeviceManager.cpp b/src/device/DeviceManager.cpp
index 9781798..eef09da 100644
--- a/src/device/DeviceManager.cpp
+++ b/src/device/DeviceManager.cpp
@@ -53,7 +53,7 @@ void DeviceManager::emitErrorCallback(const char *msg) {
 void DeviceManager::initDevice() {
 	InitLib(ErrorCallback);
 
-	deviceInfTimerID = startTimer(1000);
+	deviceInfTimerID = startTimer(10000);
 
 	// empty scan
 	connect(EventCenter::Default(), &EventCenter::RequestEmptyScan, [=](QObject* sender, QObject* detail) {
@@ -207,6 +207,7 @@ void DeviceManager::timerEvent(QTimerEvent* event) {
     //scanning progress timer
     //error exit,  callback error
     if (errorOccurred) {
+        timerID = event->timerId();
         exitScanTimer();
         return;
     }
@@ -225,14 +226,14 @@ void DeviceManager::timerEvent(QTimerEvent* event) {
             return;
         } else {
             //未发生错误并且，之前状态是扫描，代表正常扫描完成
-            if (lastStatus == SCANNING) {
+            if (lastStatus == SCANNING ) {
                 prepareFinishScan();
             }
             //一般不会出现其他情况
-            else {
-                QString msg("Unknown error in scanning progress timer");
-                THROW_ERROR(msg);
-            }
+//            else {
+//                QString msg("Unknown error in scanning progress timer");
+//                THROW_ERROR(msg);
+//            }
         }
     }
     exitScanTimer();
@@ -280,7 +281,7 @@ void DeviceManager::scanProcess(int sProgress) {
 
 void DeviceManager::exitScanTimer() {
     qDebug() << "Scanning progress Timer exit";
-    killTimer(timerID);
+    if (timerID>0)killTimer(timerID);
     timerID = -1;
     lastStatus = -1;
     previewing = false;
@@ -358,7 +359,7 @@ void DeviceManager::postScanCommand() {
         previewing = false;
         scanPhase = 1;
         qDebug() << "Start progress timer";
-        timerID = startTimer(500);
+        timerID = startTimer(2500);
         return;
     }
     //ScanControl fail
diff --git a/src/device/DeviceManager.h b/src/device/DeviceManager.h
index 6e7b64a..a9c5173 100644
--- a/src/device/DeviceManager.h
+++ b/src/device/DeviceManager.h
@@ -92,12 +92,12 @@ private:
     void scanProcess(int progress);
 
 	int scanPhase = 1;
-	int timerID = -1;
+    volatile int timerID = -1;
 	int deviceInfTimerID = -1;
 	int lastStatus = -1;
 	bool previewing = false;
 	volatile bool endLoop = false;
-	bool errorOccurred = false;
+    volatile bool errorOccurred = false;
 	QThread* previewDataCaller = nullptr;
 };