diff --git a/tests/tsim/src/simExe.c b/tests/tsim/src/simExe.c
index 2db750cdd302c63522e008e3ea324230dd87b6e5..00c9ecac5e8e29290721535e5b144ca748c0a18e 100644
--- a/tests/tsim/src/simExe.c
+++ b/tests/tsim/src/simExe.c
@@ -448,7 +448,6 @@ void simCloseNativeConnect(SScript *script) {
 
   simDebug("script:%s, taos:%p closed", script->fileName, script->taos);
   taos_close(script->taos);
-  taosMsleep(1200);
 
   script->taos = NULL;
 }
diff --git a/tests/tsim/src/simMain.c b/tests/tsim/src/simMain.c
index 33fd24dd5823b8ec7bf818cec7c36ddac783bc24..8f13254f68165a9e26ecac2406538f8cba905120 100644
--- a/tests/tsim/src/simMain.c
+++ b/tests/tsim/src/simMain.c
@@ -40,14 +40,14 @@ int32_t main(int32_t argc, char *argv[]) {
       printf("usage: %s [options] \n", argv[0]);
       printf("       [-c config]: config directory, default is: %s\n", configDir);
       printf("       [-f script]: script filename\n");
-      exit(0);
+      return 0;
     }
   }
 
   if (!simSystemInit()) {
     simError("failed to initialize the system");
     simSystemCleanUp();
-    exit(1);
+    return -1;
   }
 
   simInfo("simulator is running ...");
@@ -56,7 +56,7 @@ int32_t main(int32_t argc, char *argv[]) {
   SScript *script = simParseScript(scriptFile);
   if (script == NULL) {
     simError("parse script file:%s failed", scriptFile);
-    exit(-1);
+    return -1;
   }
 
   simScriptList[++simScriptPos] = script;
diff --git a/tests/tsim/src/simSystem.c b/tests/tsim/src/simSystem.c
index 693ade7b35a095b499198db9dcc27335f73e14bd..db5fddacb848d8ab52407c0170be0e919604d6a4 100644
--- a/tests/tsim/src/simSystem.c
+++ b/tests/tsim/src/simSystem.c
@@ -113,7 +113,7 @@ SScript *simProcessCallOver(SScript *script) {
     if (script->killed) {
       simInfo("script:" FAILED_PREFIX "%s" FAILED_POSTFIX ", " FAILED_PREFIX "failed" FAILED_POSTFIX ", error:%s",
               script->fileName, script->error);
-      exit(-1);
+      return NULL;
     } else {
       simInfo("script:" SUCCESS_PREFIX "%s" SUCCESS_POSTFIX ", " SUCCESS_PREFIX "success" SUCCESS_POSTFIX,
               script->fileName);
@@ -125,7 +125,7 @@ SScript *simProcessCallOver(SScript *script) {
       if (simScriptPos == -1) {
         simInfo("----------------------------------------------------------------------");
         simInfo("Simulation Test Done, " SUCCESS_PREFIX "%d" SUCCESS_POSTFIX " Passed:\n", simScriptSucced);
-        exit(0);
+        return NULL;
       }
 
       return simScriptList[simScriptPos];