diff --git a/rtos/code/application/source/cardv/SrcCode/UIApp/PhotoFast/PhotoFast.c b/rtos/code/application/source/cardv/SrcCode/UIApp/PhotoFast/PhotoFast.c
index 96029f3a6..d751c8135 100644
--- a/rtos/code/application/source/cardv/SrcCode/UIApp/PhotoFast/PhotoFast.c
+++ b/rtos/code/application/source/cardv/SrcCode/UIApp/PhotoFast/PhotoFast.c
@@ -1427,6 +1427,7 @@ THREAD_RETTYPE PhotoFast_FlowPreviewThread(void *arg)
 	UINT32 max_cnt = 0;
 	BOOL start_cap = FALSE;
 	BOOL stop_flag = FALSE;
+	BOOL led_flag = FALSE;
 
 #if HUNTING_CAMERA_MCU == ENABLE
     UIMenuStoreInfo *puiPara = sf_ui_para_get();
@@ -1547,7 +1548,7 @@ THREAD_RETTYPE PhotoFast_FlowPreviewThread(void *arg)
 			VOS_TICK t1, t2;
 			UINT32 duration;
 			UINT32 led_delay = 170;
-
+            led_flag = FALSE;
 			vos_perf_mark(&t1);
 
 			/**************************************************
@@ -1566,7 +1567,8 @@ THREAD_RETTYPE PhotoFast_FlowPreviewThread(void *arg)
 				if((duration >= period) ||((period - duration) <= (led_delay + 17))
 
 				){
-					if(sf_is_night_mode(0) ==TRUE){
+					if((FALSE == led_flag) && (sf_is_night_mode(0) ==TRUE)){
+                        led_flag = TRUE;
 						sf_ir_led_set(((2 == puiPara->NightMode) ? 2 : 1),puiPara->FlashLed, puiPara->NightMode,0);
 					}