diff --git a/Core/Inc/navikit.h b/Core/Inc/navikit.h
index d7db43a..9743d82 100644
--- a/Core/Inc/navikit.h
+++ b/Core/Inc/navikit.h
@@ -112,7 +112,7 @@ void NaviKit_var_init();
 //power state machine switch function
 void enter_isp_state();
 void enter_runing_state();
-void enter_shutdown_state();
+void enter_shutdown_state(uint8_t timeout = 0);
 void enter_sleep_state();
 void enter_dfu_state();
 
diff --git a/Core/Src/freertos.c b/Core/Src/freertos.c
index c94d08d..4f0944d 100644
--- a/Core/Src/freertos.c
+++ b/Core/Src/freertos.c
@@ -479,8 +479,8 @@ void StartStateSwitchTask(void *argument)
 		  {
 			  case shutdown:
 			  {//only from running state
-          if(NaviKit.sys.sta == running)
-            enter_shutdown_state();
+			  if((NaviKit.sys.sta == running))// && (NaviKit.som.shutdown_req == true)
+				enter_shutdown_state();
           }break;
 			  case running:
 			  {//from sleep and shutdown state
diff --git a/Core/Src/navikit.c b/Core/Src/navikit.c
index 0dfb15b..37008d4 100644
--- a/Core/Src/navikit.c
+++ b/Core/Src/navikit.c
@@ -52,18 +52,18 @@ void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin)
 {
 	if(GPIO_Pin == SOM_SHUTDOWN_REQ_Pin)
 	{
-		if(HAL_GPIO_ReadPin(SOM_SHUTDOWN_REQ_GPIO_Port, SOM_SHUTDOWN_REQ_Pin)==GPIO_PIN_SET)
-		{//Rising edge trigger
-//			NaviKit.som.shutdown_req = true;
-
-		}
 		if(HAL_GPIO_ReadPin(SOM_SHUTDOWN_REQ_GPIO_Port, SOM_SHUTDOWN_REQ_Pin)==GPIO_PIN_RESET)
 		{//falling edge trigger
-//			NaviKit.som.shutdown_req = false;
 			  if(NaviKit.sys.sta == running)
-			  {
-				  NaviKit.sys.next_sta = shutdown;
+			  {//if jetson nano shutdown output low,the power_en should be set low less than 10us
+				    HAL_GPIO_WritePin(SOM_POWER_EN_GPIO_Port ,SOM_POWER_EN_Pin, GPIO_PIN_RESET);
+					NaviKit.sys.next_sta = shutdown;
+					printf("som request to shutdown");
 			  }
+				NaviKit.som.shutdown_req = true;
+		}
+		else{//Rising edge trigger
+			NaviKit.som.shutdown_req = false;
 		}
 
 	}
@@ -129,10 +129,10 @@ void enter_isp_state()
     }
 }
 
-
-void enter_shutdown_state()
+//timeout:the time of wait
+void enter_shutdown_state(uint8_t timeout)
 {
-				  printf("Enter to shutdown state \n");
+				  printf("Enter to shutdown state\n");
 				  Beep(50);
 
     HAL_GPIO_WritePin(SOM_POWER_EN_GPIO_Port ,SOM_POWER_EN_Pin, GPIO_PIN_RESET);				  osDelay(100);
@@ -165,6 +165,7 @@ void enter_shutdown_state()
     HAL_GPIO_WritePin(PMB_PS_ON_GPIO_Port ,PMB_PS_ON_Pin, GPIO_PIN_RESET);                    osDelay(100);
 
 }
+
 void enter_sleep_state()
 {
 				  printf("Enter to sleep state \n");