diff --git a/code/application/source/sf_app/code/source/app/sf_service.c b/code/application/source/sf_app/code/source/app/sf_service.c
index 473385bd5..5604c330e 100755
--- a/code/application/source/sf_app/code/source/app/sf_service.c
+++ b/code/application/source/sf_app/code/source/app/sf_service.c
@@ -90,7 +90,7 @@ SINT32 app_ttyusb_IsOpen(void) {
     MLOGD("ttyUSB has not been init, will init ttyUSB!\n");
 
     UINT8 i = 0;
-
+    RETRY:
     for (i = 0; i < 150; i++) {
         if (access("/dev/ttyUSB2", F_OK) == SF_SUCCESS) {
             printf("tty usb ko exist!\r\n");
@@ -111,9 +111,12 @@ SINT32 app_ttyusb_IsOpen(void) {
         if ((0 == retryFlag) && (retryTime >= 100) &&
             (retryTime % 100 == 0)) // 200ms*100 = 20s
         {
-            MLOGE("-------ttyUSB init fail, clos usb mux.\n");
-            sf_ttyusb_restart();
+            MLOGE("-------ttyUSB init fail, reset module.\n");
+            sf_mcu_reg_set(SF_MCU_RESET_MODULE, 0);
+            sleep(5);
             retryFlag = 1;
+            retryTime = 0;
+            goto RETRY;
         } else if ((1 == retryFlag) && (retryTime >= 50) &&
                     (retryTime % 50 == 0)) // 200ms*25 = 5s
         {