diff --git a/frameworks/inputmethod_ability/include/input_method_ability.h b/frameworks/inputmethod_ability/include/input_method_ability.h
index 00674e9..01bfd53 100644
--- a/frameworks/inputmethod_ability/include/input_method_ability.h
+++ b/frameworks/inputmethod_ability/include/input_method_ability.h
@@ -53,6 +53,7 @@ namespace MiscServices {
         int32_t displyId = 0;
         sptr<IRemoteObject> startInputToken;
         InputChannel *writeInputChannel;
+        bool stop_;
 
         // communicating with IMSA
         sptr<IInputControlChannel> inputControlChannel;
diff --git a/frameworks/inputmethod_ability/src/input_method_ability.cpp b/frameworks/inputmethod_ability/src/input_method_ability.cpp
index 4749eaf..9e2c15c 100644
--- a/frameworks/inputmethod_ability/src/input_method_ability.cpp
+++ b/frameworks/inputmethod_ability/src/input_method_ability.cpp
@@ -29,7 +29,7 @@ namespace MiscServices {
     sptr<InputMethodAbility> InputMethodAbility::instance_;
     std::mutex InputMethodAbility::instanceLock_;
 
-    InputMethodAbility::InputMethodAbility()
+    InputMethodAbility::InputMethodAbility() : stop_(false)
     {
         Initialize();
         OnConnect();
@@ -41,6 +41,7 @@ namespace MiscServices {
             delete msgHandler;
             msgHandler = nullptr;
         }
+        stop_ = true;
     }
 
     sptr<InputMethodAbility> InputMethodAbility::GetInstance()
@@ -109,7 +110,7 @@ namespace MiscServices {
 
     void InputMethodAbility::WorkThread()
     {
-        while (1) {
+        while (!stop_) {
             Message *msg = msgHandler->GetMessage();
             switch (msg->msgId_) {
                 case MSG_ID_INITIALIZE_INPUT: {
diff --git a/frameworks/inputmethod_ability/src/input_method_core_stub.cpp b/frameworks/inputmethod_ability/src/input_method_core_stub.cpp
index d1d0862..bf51a66 100644
--- a/frameworks/inputmethod_ability/src/input_method_core_stub.cpp
+++ b/frameworks/inputmethod_ability/src/input_method_core_stub.cpp
@@ -33,6 +33,7 @@ namespace MiscServices {
     InputMethodCoreStub::InputMethodCoreStub(int userId)
     {
         userId_ = userId;
+        msgHandler_ = nullptr;
     }
 
     InputMethodCoreStub::~InputMethodCoreStub()
diff --git a/frameworks/inputmethod_controller/include/input_method_controller.h b/frameworks/inputmethod_controller/include/input_method_controller.h
index 31a4e05..84f9902 100644
--- a/frameworks/inputmethod_controller/include/input_method_controller.h
+++ b/frameworks/inputmethod_controller/include/input_method_controller.h
@@ -77,6 +77,7 @@ namespace MiscServices {
         static sptr<InputMethodController> instance_;
         std::thread workThreadHandler;
         MessageHandler *msgHandler;
+        bool stop_;
     };
 }
 }
diff --git a/frameworks/inputmethod_controller/src/input_method_controller.cpp b/frameworks/inputmethod_controller/src/input_method_controller.cpp
index 4e45b62..23c6948 100644
--- a/frameworks/inputmethod_controller/src/input_method_controller.cpp
+++ b/frameworks/inputmethod_controller/src/input_method_controller.cpp
@@ -24,7 +24,7 @@ using namespace MessageID;
     sptr<InputMethodController> InputMethodController::instance_;
     std::mutex InputMethodController::instanceLock_;
 
-    InputMethodController::InputMethodController()
+    InputMethodController::InputMethodController() : stop_(false)
     {
         IMSA_HILOGI("InputMethodController structure");
         Initialize();
@@ -35,6 +35,7 @@ using namespace MessageID;
         if (msgHandler != nullptr) {
             delete msgHandler;
             msgHandler = nullptr;
+            stop_ = false;
         }
     }
 
@@ -97,7 +98,7 @@ using namespace MessageID;
 
     void InputMethodController::WorkThread()
     {
-        while (1) {
+        while (!stop_) {
             Message *msg = msgHandler->GetMessage();
             switch (msg->msgId_) {
                 case MSG_ID_INSERT_CHAR: {
diff --git a/frameworks/inputmethod_controller/src/input_method_system_ability_proxy.cpp b/frameworks/inputmethod_controller/src/input_method_system_ability_proxy.cpp
index 96161a9..3ae9c12 100644
--- a/frameworks/inputmethod_controller/src/input_method_system_ability_proxy.cpp
+++ b/frameworks/inputmethod_controller/src/input_method_system_ability_proxy.cpp
@@ -303,7 +303,7 @@ namespace MiscServices {
 
         KeyboardType *keyType = reply.ReadParcelable<KeyboardType>();
         if (keyType == nullptr) {
-            return ERROR_STATUS_BAD_INDEX;
+            return ERROR_NULL_POINTER;
         }
         *retType = *keyType;
         delete keyType;
diff --git a/interfaces/kits/js/napi/js_input_method_engine.cpp b/interfaces/kits/js/napi/js_input_method_engine.cpp
index 2941f56..00394d2 100644
--- a/interfaces/kits/js/napi/js_input_method_engine.cpp
+++ b/interfaces/kits/js/napi/js_input_method_engine.cpp
@@ -171,7 +171,6 @@ namespace MiscServices {
             eventTarget->Off(type);
         }
 
-        delete type;
         delete type;
         type = nullptr;
         napi_value result = nullptr;
diff --git a/services/src/input_method_system_ability.cpp b/services/src/input_method_system_ability.cpp
index 487bfd0..fee4092 100644
--- a/services/src/input_method_system_ability.cpp
+++ b/services/src/input_method_system_ability.cpp
@@ -583,11 +583,16 @@ namespace MiscServices {
         if (it != msgHandlers.end()) {
             MessageHandler *handler = it->second;
             Message *destMsg = new Message(MSG_ID_USER_LOCK , nullptr);
-            handler->SendMessage(destMsg);
-            GetUserSession(userId)->JoinWorkThread();
-            msgHandlers.erase(it);
-            delete handler;
-            handler = nullptr;
+            if (destMsg != nullptr) {
+                handler->SendMessage(destMsg);
+                PerUserSession *userSession = GetUserSession(userId);
+                if (userSession != nullptr) {
+                    userSession->JoinWorkThread();
+                }
+                msgHandlers.erase(it);
+                delete handler;
+                handler = nullptr;
+            }
         }
         setting->OnUserLocked();
         IMSA_HILOGI("End...[%d]\n", userId);
@@ -705,6 +710,10 @@ namespace MiscServices {
     {
         IMSA_HILOGI("Start...\n");
         MessageParcel *data = msg->msgContent_;
+        if (data == nullptr) {
+            IMSA_HILOGI("InputMethodSystemAbility::OnPackageRemoved data is nullptr");
+            return ErrorCode::ERROR_NULL_POINTER;
+        }
         int32_t userId = data->ReadInt32();
         int32_t size = data->ReadInt32();
 
@@ -719,6 +728,10 @@ namespace MiscServices {
             return ErrorCode::ERROR_USER_NOT_UNLOCKED;
         }
         PerUserSession *session = GetUserSession(userId);
+        if (session == nullptr) {
+            IMSA_HILOGI("InputMethodSystemAbility::OnPackageRemoved session is nullptr");
+            return ErrorCode::ERROR_NULL_POINTER;
+        }
         session->OnPackageRemoved(packageName);
         bool securityImeFlag = false;
         int32_t ret = setting->OnPackageRemoved(packageName, securityImeFlag);
diff --git a/services/src/peruser_session.cpp b/services/src/peruser_session.cpp
index fb80334..d4d1f8f 100644
--- a/services/src/peruser_session.cpp
+++ b/services/src/peruser_session.cpp
@@ -977,8 +977,8 @@ namespace MiscServices {
     */
     int PerUserSession::IncreaseOrResetImeError(bool resetFlag, int imeIndex)
     {
-        static int errorNum[MIN_IME] = {0, 0};
-        static time_t past[MIN_IME] = {time(0), time(0)};
+        static int errorNum[2] = {0, 0};
+        static time_t past[2] = {time(0), time(0)};
         if (resetFlag == true) {
             errorNum[imeIndex] = 0;
             past[imeIndex] = 0;