diff --git a/dm/test/systemtest/display_change_test.cpp b/dm/test/systemtest/display_change_test.cpp
index 857cb4a0..f6396268 100644
--- a/dm/test/systemtest/display_change_test.cpp
+++ b/dm/test/systemtest/display_change_test.cpp
@@ -220,6 +220,7 @@ HWTEST_F(DisplayChangeTest, CheckDisplayStateChange01, Function | SmallTest | Le
 {
     WLOGFI("CheckDisplayStateChange01");
     sptr<Display> defaultDisplay = DisplayManager::GetInstance().GetDisplayById(defaultDisplayId_);
+    ASSERT_NE(nullptr, defaultDisplay);
     ScreenId screenId = defaultDisplay->GetScreenId();
     sptr<Screen> screen = ScreenManager::GetInstance().GetScreenById(screenId);
     ASSERT_NE(nullptr, screen);
@@ -238,6 +239,7 @@ HWTEST_F(DisplayChangeTest, CheckDisplayStateChange02, Function | SmallTest | Le
 {
     WLOGFI("CheckDisplayStateChange02");
     sptr<Display> defaultDisplay = DisplayManager::GetInstance().GetDisplayById(defaultDisplayId_);
+    ASSERT_NE(nullptr, defaultDisplay);
     ScreenId screenId = defaultDisplay->GetScreenId();
     sptr<Screen> screen = ScreenManager::GetInstance().GetScreenById(screenId);
     ASSERT_NE(nullptr, screen);
@@ -270,6 +272,7 @@ HWTEST_F(DisplayChangeTest, CheckDisplaySizeChange01, Function | MediumTest | Le
 {
     WLOGFI("CheckDisplaySizeChange01");
     sptr<Display> defaultDisplay = DisplayManager::GetInstance().GetDisplayById(defaultDisplayId_);
+    ASSERT_NE(nullptr, defaultDisplay);
     ScreenId screenId = defaultDisplay->GetScreenId();
     sptr<Screen> screen = ScreenManager::GetInstance().GetScreenById(screenId);
     ASSERT_NE(nullptr, screen);
@@ -302,6 +305,7 @@ HWTEST_F(DisplayChangeTest, CheckDisplaySizeChange02, Function | MediumTest | Le
 {
     WLOGFI("CheckDisplaySizeChange02");
     sptr<Display> defaultDisplay = DisplayManager::GetInstance().GetDisplayById(defaultDisplayId_);
+    ASSERT_NE(nullptr, defaultDisplay);
     ScreenId screenId = defaultDisplay->GetScreenId();
     sptr<Screen> screen = ScreenManager::GetInstance().GetScreenById(screenId);
     ASSERT_NE(nullptr, screen);
@@ -315,6 +319,7 @@ HWTEST_F(DisplayChangeTest, CheckDisplaySizeChange02, Function | MediumTest | Le
             WLOGFI("SetScreenActiveMode: %{public}u -> %{public}u", usedModeIdx, modeIdx);
             ASSERT_EQ(true, CheckDisplayChangeEventCallback(true));
             defaultDisplay = DisplayManager::GetInstance().GetDisplayById(defaultDisplayId_);
+            ASSERT_NE(nullptr, defaultDisplay);
             ASSERT_EQ(true, DisplaySizeEqual(defaultDisplay, modes[modeIdx]));
             break;
         }
diff --git a/dm/test/unittest/display_change_unit_test.cpp b/dm/test/unittest/display_change_unit_test.cpp
index e4a21e0b..ccc7bbec 100644
--- a/dm/test/unittest/display_change_unit_test.cpp
+++ b/dm/test/unittest/display_change_unit_test.cpp
@@ -59,7 +59,9 @@ void DisplayChangeUnitTest::SetUpTestCase()
 {
     defaultDisplayId_ = DisplayManager::GetInstance().GetDefaultDisplayId();
     sptr<Display> defaultDisplay = DisplayManager::GetInstance().GetDisplayById(defaultDisplayId_);
-    defaultScreenId_ = defaultDisplay->GetScreenId();
+    if (defaultDisplay != nullptr) {
+        defaultScreenId_ = defaultDisplay->GetScreenId();
+    }
 }
 
 void DisplayChangeUnitTest::TearDownTestCase()
diff --git a/interfaces/kits/napi/window_runtime/window_manager_napi/js_window_manager.cpp b/interfaces/kits/napi/window_runtime/window_manager_napi/js_window_manager.cpp
index 218b6b2b..2233b260 100644
--- a/interfaces/kits/napi/window_runtime/window_manager_napi/js_window_manager.cpp
+++ b/interfaces/kits/napi/window_runtime/window_manager_napi/js_window_manager.cpp
@@ -330,7 +330,6 @@ NativeValue* JsWindowManager::OnMinimizeAll(NativeEngine& engine, NativeCallback
         WLOGFE("param is too small!");
         errCode = WMError::WM_ERROR_INVALID_PARAM;
     }
-    // TODO: use DisplayId instead of int64_t when engine supported
     int64_t displayId = static_cast<int64_t>(DISPLAY_ID_INVALD);
     if (errCode == WMError::WM_OK && !ConvertFromJsValue(engine, info.argv[0], displayId)) {
         WLOGFE("Failed to convert parameter to displayId");
diff --git a/wm/test/systemtest/BUILD.gn b/wm/test/systemtest/BUILD.gn
index 4aa3d3a2..60863b09 100644
--- a/wm/test/systemtest/BUILD.gn
+++ b/wm/test/systemtest/BUILD.gn
@@ -1,4 +1,4 @@
-# Copyright (c) 2021 Huawei Device Co., Ltd.
+# Copyright (c) 2021-2022 Huawei Device Co., Ltd.
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
@@ -214,7 +214,7 @@ ohos_static_library("wm_systemtest_common") {
   public_deps = [
     "//foundation/ace/ace_engine/interfaces/innerkits/ace:ace_uicontent",
 
-    # todo need delete it for abilitycontext
+    # need delete it for abilitycontext
     "//foundation/ace/napi:ace_napi",
     "//foundation/graphic/standard/rosen/modules/render_service_client:librender_service_client",
     "//foundation/multimodalinput/input/frameworks/proxy:libmmi-client",
diff --git a/wm/test/systemtest/window_focus_test.cpp b/wm/test/systemtest/window_focus_test.cpp
index e96f3c40..ed45139a 100644
--- a/wm/test/systemtest/window_focus_test.cpp
+++ b/wm/test/systemtest/window_focus_test.cpp
@@ -76,10 +76,9 @@ void WindowFocusTest::SetUpTestCase()
     if (display == nullptr) {
         WLOGFE("GetDefaultDisplay: failed!");
         return;
-    } else {
-        WLOGFI("GetDefaultDisplay: id %{public}" PRIu64", w %{public}d, h %{public}d, fps %{public}u",
-            display->GetId(), display->GetWidth(), display->GetHeight(), display->GetFreshRate());
     }
+    WLOGFI("GetDefaultDisplay: id %{public}" PRIu64", w %{public}d, h %{public}d, fps %{public}u",
+        display->GetId(), display->GetWidth(), display->GetHeight(), display->GetFreshRate());
     Rect displayRect = {0, 0, display->GetWidth(), display->GetHeight()};
     utils::InitByDisplayRect(displayRect);
 }
diff --git a/wm/test/systemtest/window_immersive_test.cpp b/wm/test/systemtest/window_immersive_test.cpp
index 8ae3a159..aface79c 100644
--- a/wm/test/systemtest/window_immersive_test.cpp
+++ b/wm/test/systemtest/window_immersive_test.cpp
@@ -163,10 +163,10 @@ void WindowImmersiveTest::SetUpTestCase()
     auto display = DisplayManager::GetInstance().GetDisplayById(0);
     if (display == nullptr) {
         WLOGFE("GetDefaultDisplay: failed!");
-    } else {
-        WLOGFI("GetDefaultDisplay: id %{public}" PRIu64", w %{public}d, h %{public}d, fps %{public}u",
-            display->GetId(), display->GetWidth(), display->GetHeight(), display->GetFreshRate());
+        return;
     }
+    WLOGFI("GetDefaultDisplay: id %{public}" PRIu64", w %{public}d, h %{public}d, fps %{public}u",
+        display->GetId(), display->GetWidth(), display->GetHeight(), display->GetFreshRate());
     Rect displayRect = {0, 0, display->GetWidth(), display->GetHeight()};
     utils::InitByDisplayRect(displayRect);
 }
diff --git a/wm/test/systemtest/window_input_method_test.cpp b/wm/test/systemtest/window_input_method_test.cpp
index a445d05c..c0405c37 100644
--- a/wm/test/systemtest/window_input_method_test.cpp
+++ b/wm/test/systemtest/window_input_method_test.cpp
@@ -38,10 +38,9 @@ void WindowInputMethodTest::SetUpTestCase()
     if (display == nullptr) {
         printf("GetDefaultDisplay: failed!\n");
         return;
-    } else {
-        printf("GetDefaultDisplay: id %llu, w %d, h %d, fps %u\n", display->GetId(), display->GetWidth(),
-            display->GetHeight(), display->GetFreshRate());
     }
+    printf("GetDefaultDisplay: id %llu, w %d, h %d, fps %u\n", display->GetId(), display->GetWidth(),
+        display->GetHeight(), display->GetFreshRate());
     Rect displayRect = {0, 0, display->GetWidth(), display->GetHeight()};
     utils::InitByDisplayRect(displayRect);
 }
diff --git a/wm/test/systemtest/window_layout_test.cpp b/wm/test/systemtest/window_layout_test.cpp
index 136425cf..9412d440 100644
--- a/wm/test/systemtest/window_layout_test.cpp
+++ b/wm/test/systemtest/window_layout_test.cpp
@@ -42,10 +42,10 @@ void WindowLayoutTest::SetUpTestCase()
     auto display = DisplayManager::GetInstance().GetDisplayById(0);
     if (display == nullptr) {
         printf("GetDefaultDisplay: failed!\n");
-    } else {
-        printf("GetDefaultDisplay: id %llu, w %d, h %d, fps %u\n", display->GetId(), display->GetWidth(),
-            display->GetHeight(), display->GetFreshRate());
+        return;
     }
+    printf("GetDefaultDisplay: id %llu, w %d, h %d, fps %u\n", display->GetId(), display->GetWidth(),
+        display->GetHeight(), display->GetFreshRate());
     Rect displayRect = {0, 0, display->GetWidth(), display->GetHeight()};
     utils::InitByDisplayRect(displayRect);
 
diff --git a/wm/test/systemtest/window_move_drag_test.cpp b/wm/test/systemtest/window_move_drag_test.cpp
index fabc81c5..43d7e2d7 100644
--- a/wm/test/systemtest/window_move_drag_test.cpp
+++ b/wm/test/systemtest/window_move_drag_test.cpp
@@ -78,10 +78,10 @@ void WindowMoveDragTest::SetUp()
     auto display = DisplayManager::GetInstance().GetDisplayById(0);
     if (display == nullptr) {
         WLOGFE("GetDefaultDisplay: failed!\n");
-    } else {
-        WLOGFI("GetDefaultDisplay: id %{public}llu, w %{public}d, h %{public}d, fps %{public}u\n",
-               display->GetId(), display->GetWidth(), display->GetHeight(), display->GetFreshRate());
+        return;
     }
+    WLOGFI("GetDefaultDisplay: id %{public}llu, w %{public}d, h %{public}d, fps %{public}u\n",
+        display->GetId(), display->GetWidth(), display->GetHeight(), display->GetFreshRate());
     Rect displayRect = {0, 0, display->GetWidth(), display->GetHeight()};
     utils::InitByDisplayRect(displayRect);
 
diff --git a/wm/test/systemtest/window_test_utils.cpp b/wm/test/systemtest/window_test_utils.cpp
index a2c75e80..e096ca81 100644
--- a/wm/test/systemtest/window_test_utils.cpp
+++ b/wm/test/systemtest/window_test_utils.cpp
@@ -275,10 +275,10 @@ void WindowTestUtils::InitSplitRects()
     auto display = DisplayManager::GetInstance().GetDisplayById(0);
     if (display == nullptr) {
         WLOGFE("GetDefaultDisplay: failed!");
-    } else {
-        WLOGFI("GetDefaultDisplay: id %{public}" PRIu64", w %{public}d, h %{public}d, fps %{public}u",
-            display->GetId(), display->GetWidth(), display->GetHeight(), display->GetFreshRate());
+        return;
     }
+    WLOGFI("GetDefaultDisplay: id %{public}" PRIu64", w %{public}d, h %{public}d, fps %{public}u",
+        display->GetId(), display->GetWidth(), display->GetHeight(), display->GetFreshRate());
 
     Rect displayRect = {0, 0, display->GetWidth(), display->GetHeight()};
     displayRect_ = displayRect;
diff --git a/wm/test/systemtest/window_visibility_info_test.cpp b/wm/test/systemtest/window_visibility_info_test.cpp
index 360cc587..ec98a552 100644
--- a/wm/test/systemtest/window_visibility_info_test.cpp
+++ b/wm/test/systemtest/window_visibility_info_test.cpp
@@ -69,10 +69,10 @@ void WindowVisibilityInfoTest::SetUpTestCase()
     auto display = DisplayManager::GetInstance().GetDisplayById(0);
     if (display == nullptr) {
         WLOGFE("GetDefaultDisplay: failed!");
-    } else {
-        WLOGFI("GetDefaultDisplay: id %{public}" PRIu64", w %{public}d, h %{public}d, fps %{public}u",
-            display->GetId(), display->GetWidth(), display->GetHeight(), display->GetFreshRate());
+        return;
     }
+    WLOGFI("GetDefaultDisplay: id %{public}" PRIu64", w %{public}d, h %{public}d, fps %{public}u",
+        display->GetId(), display->GetWidth(), display->GetHeight(), display->GetFreshRate());
     Rect displayRect = {0, 0,
                         static_cast<uint32_t>(display->GetWidth()), static_cast<uint32_t>(display->GetHeight())};
     utils::InitByDisplayRect(displayRect);
diff --git a/wm/test/unittest/BUILD.gn b/wm/test/unittest/BUILD.gn
index 8223f95a..f7cd3817 100644
--- a/wm/test/unittest/BUILD.gn
+++ b/wm/test/unittest/BUILD.gn
@@ -1,4 +1,4 @@
-# Copyright (c) 2021 Huawei Device Co., Ltd.
+# Copyright (c) 2021-2022 Huawei Device Co., Ltd.
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
diff --git a/wm/test/unittest/window_impl_test.cpp b/wm/test/unittest/window_impl_test.cpp
index badd6769..9db53054 100644
--- a/wm/test/unittest/window_impl_test.cpp
+++ b/wm/test/unittest/window_impl_test.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021 Huawei Device Co., Ltd.
+ * Copyright (c) 2021-2022 Huawei Device Co., Ltd.
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
diff --git a/wmserver/src/drag_controller.cpp b/wmserver/src/drag_controller.cpp
index 481f91ca..dd5a0390 100644
--- a/wmserver/src/drag_controller.cpp
+++ b/wmserver/src/drag_controller.cpp
@@ -138,4 +138,4 @@ bool DragController::GetHitPoint(uint32_t windowId, PointInfo& point)
     return true;
 }
 }
-}
\ No newline at end of file
+}
diff --git a/wmserver/src/window_node_container.cpp b/wmserver/src/window_node_container.cpp
index 6be9ea74..95862bdb 100644
--- a/wmserver/src/window_node_container.cpp
+++ b/wmserver/src/window_node_container.cpp
@@ -242,7 +242,7 @@ WMError WindowNodeContainer::DestroyWindowNode(sptr<WindowNode>& node, std::vect
 
 WMError WindowNodeContainer::RemoveWindowNode(sptr<WindowNode>& node)
 {
-    if (node == nullptr || !node->surfaceNode_) {
+    if (node == nullptr) {
         WLOGFE("window node or surface node is nullptr, invalid");
         return WMError::WM_ERROR_DESTROYED_OBJECT;
     }