diff --git a/visa/visa-server/src/main/java/cn/axzo/nanopart/visa/server/ess/EssCallbackController.java b/visa/visa-server/src/main/java/cn/axzo/nanopart/visa/server/ess/EssCallbackController.java
index d093addb..b1818d10 100644
--- a/visa/visa-server/src/main/java/cn/axzo/nanopart/visa/server/ess/EssCallbackController.java
+++ b/visa/visa-server/src/main/java/cn/axzo/nanopart/visa/server/ess/EssCallbackController.java
@@ -101,6 +101,8 @@ class EssCallbackController implements EssCallbackApi, InitializingBean {
 
     @Override
     public ApiResult<Object> callback(CallbackContent content) {
+        if (content.getEncrypt() == null || content.getEncrypt().length() < 20)
+            return ApiResult.ok("success");
         String requestBody = Base64Decoder.decodeStr(content.getEncrypt());
         log.info("ess callback: {}", requestBody);
         CallbackRequest request = JSON.parseObject(requestBody, CallbackRequest.class);