diff --git a/src/main/java/com/kimgo/wepush/controller/SMSController.java b/src/main/java/com/kimgo/wepush/controller/SMSController.java
index caf9c88..029f022 100644
--- a/src/main/java/com/kimgo/wepush/controller/SMSController.java
+++ b/src/main/java/com/kimgo/wepush/controller/SMSController.java
@@ -25,7 +25,7 @@ public class SMSController {
         if(accessToken == null){
             return ServerResponseEntity.fail("accessToken cannot be empty.");
         }
-        if (!smsInfo.isNullString()){
+        if (smsInfo.isNullString()){
             return ServerResponseEntity.fail("json body value error.");
         }
         if (smsInfo == null || !smsInfo.validateFields()) {