diff --git a/ext/pin_auth/src/pin_auth.cpp b/ext/pin_auth/src/pin_auth.cpp
index b67ee490..377cb8fd 100644
--- a/ext/pin_auth/src/pin_auth.cpp
+++ b/ext/pin_auth/src/pin_auth.cpp
@@ -16,6 +16,7 @@
 #include "pin_auth.h"
 
 #include <memory>
+#include <cstring>
 
 #include "dm_constants.h"
 #include "dm_log.h"
@@ -65,14 +66,18 @@ int32_t PinAuth::StartAuth(std::string &authToken, std::shared_ptr<DmAuthManager
 int32_t PinAuth::VerifyAuthentication(std::string &authToken, const std::string &authParam)
 {
     times_ += 1;
-    nlohmann::json authParamJson = nlohmann::json::parse(authParam, nullptr, false);
-    if (authParamJson.is_discarded()) {
+    if (strlen(authParam.c_str()) == 1) {
         if (authParam == "0") {
             return DM_OK;
         }
         LOGE("Peer rejection");
         return DM_FAILED;
     }
+    nlohmann::json authParamJson = nlohmann::json::parse(authParam, nullptr, false);
+    if (authParamJson.is_discarded()) {
+        LOGE("DecodeRequestAuth jsonStr error");
+        return DM_FAILED;
+    }
     nlohmann::json authTokenJson = nlohmann::json::parse(authToken, nullptr, false);
     if (authTokenJson.is_discarded()) {
         LOGE("DecodeRequestAuth jsonStr error");