diff --git a/components/cascader/cascader.component.ts b/components/cascader/cascader.component.ts
index 41e4505b37..b2530d54f2 100644
--- a/components/cascader/cascader.component.ts
+++ b/components/cascader/cascader.component.ts
@@ -365,10 +365,9 @@ export class NzCascaderComponent implements NzCascaderComponentAsSource, OnInit,
       // These operations would not mutate data.
       this.checkChildren();
       this.setDisplayLabel();
+      this.cdr.detectChanges();
       this.reposition();
       this.setDropdownStyles();
-
-      this.cdr.markForCheck();
     });
 
     srv.$loading.pipe(takeUntil(this.destroy$)).subscribe(loading => {
@@ -587,6 +586,7 @@ export class NzCascaderComponent implements NzCascaderComponentAsSource, OnInit,
     if (option && option.disabled) {
       return;
     }
+
     this.el.focus();
     this.inSearchingMode
       ? this.cascaderService.setSearchOptionSelected(option as NzCascaderSearchOption)
@@ -711,6 +711,7 @@ export class NzCascaderComponent implements NzCascaderComponentAsSource, OnInit,
     if (this.overlay && this.overlay.overlayRef && this.menuVisible) {
       Promise.resolve().then(() => {
         this.overlay.overlayRef.updatePosition();
+        this.cdr.markForCheck();
       });
     }
   }
diff --git a/components/cascader/cascader.service.ts b/components/cascader/cascader.service.ts
index 3dad28c3b6..e89b7812f0 100644
--- a/components/cascader/cascader.service.ts
+++ b/components/cascader/cascader.service.ts
@@ -173,7 +173,6 @@ export class NzCascaderService implements OnDestroy {
     if (option.disabled) {
       return;
     }
-
     this.activatedOptions[columnIndex] = option;
     this.trackAncestorActivatedOptions(columnIndex);
     this.dropBehindActivatedOptions(columnIndex);
diff --git a/components/core/overlay/overlay-position.ts b/components/core/overlay/overlay-position.ts
index f9c7a9a4fe..4ca5ab08c0 100644
--- a/components/core/overlay/overlay-position.ts
+++ b/components/core/overlay/overlay-position.ts
@@ -44,7 +44,9 @@ export const DEFAULT_CASCADER_POSITIONS = [
   POSITION_MAP.bottomLeft,
   POSITION_MAP.bottomRight,
   POSITION_MAP.topLeft,
-  POSITION_MAP.topRight
+  POSITION_MAP.topRight,
+  POSITION_MAP.topCenter,
+  POSITION_MAP.bottomCenter
 ];
 
 export const DEFAULT_MENTION_TOP_POSITIONS = [
diff --git a/components/tooltip/doc/index.zh-CN.md b/components/tooltip/doc/index.zh-CN.md
index 1b6493fe6e..42b0846d26 100644
--- a/components/tooltip/doc/index.zh-CN.md
+++ b/components/tooltip/doc/index.zh-CN.md
@@ -27,7 +27,7 @@ import { NzToolTipModule } from 'ng-zorro-antd/tooltip';
 | `[nzTooltipArrowPointAtCenter]` | 箭头指向锚点的中心 | `boolean` | `false` |
 | `[nzTooltipTitle]` | 提示文字 | `string \| TemplateRef<void>` | - |
 | `[nzTooltipTitleContext]` | 提示文字模板上下文 | `object` | - |
-| `[nzTooltipTrigger]` | 触发行为，可选 `hover/focus/click`，为 `null` 时不响应光标事件 | `'click' \| 'focus' \| 'hover' \| null` | `'hover'` |
+| `[nzTooltipTrigger]` | 触发行为，可选 `hover` \| `focus` \| `click`，为 `null` 时不响应光标事件 | `'click' \| 'focus' \| 'hover' \| null` | `'hover'` |
 | `[nzTooltipPlacement]` | 气泡框位置 | `'top' \| 'left' \| 'right' \| 'bottom' \| 'topLeft' \| 'topRight' \| 'bottomLeft' \| 'bottomRight' \| 'leftTop' \| 'leftBottom' \| 'rightTop' \| 'rightBottom' \| Array<string>` | `'top'` |
 | `[nzTooltipColor]` | 背景颜色	| `string` | - |
 | `[nzTooltipOrigin]` | 气泡框定位元素 | `ElementRef` | - |