diff --git a/app/demolink/demosdk.c b/app/demolink/demosdk.c
index beb196f68fd0f7845cad2678df21ceddb80ffff8..def99bb3e47496765700a0509df393fb152ae6cf 100644
--- a/app/demolink/demosdk.c
+++ b/app/demolink/demosdk.c
@@ -22,13 +22,11 @@
 #define TASK_PRIO 20
 #define SECOND_CNT 1000
 
-void *DemoSdkBiz(const char *arg)
+static void *DemoSdkBiz(const char *arg)
 {
     (void)arg;
-    while (1) {
-        printf("it is demo biz: hello world.\n");
-        DemoSdkSleepMs(SECOND_CNT);
-    }
+    printf("it is demo biz: hello world.\n");
+    DemoSdkSleepMs(SECOND_CNT);
     return NULL;
 }
 
diff --git a/app/demolink/helloworld.c b/app/demolink/helloworld.c
index f1deceadc62b5cdb0098cb0b9838465532b5bf1f..95f4cc2c229f8f5cb19ee00e75a0965c24abc802 100644
--- a/app/demolink/helloworld.c
+++ b/app/demolink/helloworld.c
@@ -16,7 +16,7 @@
 #include "ohos_init.h"
 #include "demosdk.h"
 
-void DemoSdkMain(void)
+static void DemoSdkMain(void)
 {
     DemoSdkEntry();
 }
diff --git a/app/iothardware/led_example.c b/app/iothardware/led_example.c
index 3ef20577e3adb5482be2012a61a1ee2fa88fd1c1..921c3acce3abeef5ee6e6209e99c2d4685f8dac1 100644
--- a/app/iothardware/led_example.c
+++ b/app/iothardware/led_example.c
@@ -35,26 +35,24 @@ enum LedState g_ledState = LED_SPARK;
 static void *LedTask(const char *arg)
 {
     (void)arg;
-    while (1) {
-        switch (g_ledState) {
-            case LED_ON:
-                IoTGpioSetOutputVal(LED_TEST_GPIO, 1);
-                usleep(LED_INTERVAL_TIME_US);
-                break;
-            case LED_OFF:
-                IoTGpioSetOutputVal(LED_TEST_GPIO, 0);
-                usleep(LED_INTERVAL_TIME_US);
-                break;
-            case LED_SPARK:
-                IoTGpioSetOutputVal(LED_TEST_GPIO, 0);
-                usleep(LED_INTERVAL_TIME_US);
-                IoTGpioSetOutputVal(LED_TEST_GPIO, 1);
-                usleep(LED_INTERVAL_TIME_US);
-                break;
-            default:
-                usleep(LED_INTERVAL_TIME_US);
-                break;
-        }
+    switch (g_ledState) {
+        case LED_ON:
+            IoTGpioSetOutputVal(LED_TEST_GPIO, 1);
+            usleep(LED_INTERVAL_TIME_US);
+            break;
+        case LED_OFF:
+            IoTGpioSetOutputVal(LED_TEST_GPIO, 0);
+            usleep(LED_INTERVAL_TIME_US);
+            break;
+        case LED_SPARK:
+            IoTGpioSetOutputVal(LED_TEST_GPIO, 0);
+            usleep(LED_INTERVAL_TIME_US);
+            IoTGpioSetOutputVal(LED_TEST_GPIO, 1);
+            usleep(LED_INTERVAL_TIME_US);
+            break;
+        default:
+            usleep(LED_INTERVAL_TIME_US);
+            break;
     }
 
     return NULL;
diff --git a/app/samgr/feature_example.c b/app/samgr/feature_example.c
index 692f46986e1273815e729755bdc3dc30197afa4e..a026893635bf962c703ec22b9162460d6a91b890 100644
--- a/app/samgr/feature_example.c
+++ b/app/samgr/feature_example.c
@@ -271,7 +271,7 @@ static void CASE_AsyncTimeCall(DemoApi *demoApi)
     demoApi->AsyncTimeCall((IUnknown *)demoApi);
 }
 
-void AsyncHandler(const Request *request, const Response *response)
+static void AsyncHandler(const Request *request, const Response *response)
 {
     (void)request;
     printf("[LPC Test][TaskID:%u][Step:%u][AsyncCallBack]Success! Response:%s \n",