diff --git a/components/core/addon/string_template_outlet.ts b/components/core/addon/string_template_outlet.ts
index 87e491f1ffb..6171d2d5a96 100644
--- a/components/core/addon/string_template_outlet.ts
+++ b/components/core/addon/string_template_outlet.ts
@@ -66,12 +66,30 @@ export class NzStringTemplateOutletDirective implements OnChanges {
     }
   }
 
+  // tslint:disable-next-line:no-any
+  private getType(value: string | TemplateRef<any>): 'template' | 'string' {
+    if (value instanceof TemplateRef) {
+      return 'template';
+    } else {
+      return 'string';
+    }
+  }
+
   private shouldRecreateView(changes: SimpleChanges): boolean {
     const { nzStringTemplateOutletContext, nzStringTemplateOutlet } = changes;
-    return (
-      !!nzStringTemplateOutlet ||
-      (nzStringTemplateOutletContext && this.hasContextShapeChanged(nzStringTemplateOutletContext))
-    );
+    let shouldOutletRecreate = false;
+    if (nzStringTemplateOutlet) {
+      if (nzStringTemplateOutlet.firstChange) {
+        shouldOutletRecreate = true;
+      } else {
+        const previousOutletType = this.getType(nzStringTemplateOutlet.previousValue);
+        const currentOutletType = this.getType(nzStringTemplateOutlet.currentValue);
+        shouldOutletRecreate = !(previousOutletType === 'string' && currentOutletType === 'string');
+      }
+    }
+    const shouldContextRecreate =
+      nzStringTemplateOutletContext && this.hasContextShapeChanged(nzStringTemplateOutletContext);
+    return shouldContextRecreate || shouldOutletRecreate;
   }
 
   private hasContextShapeChanged(ctxChange: SimpleChange): boolean {
@@ -102,7 +120,6 @@ export class NzStringTemplateOutletDirective implements OnChanges {
 
   ngOnChanges(changes: SimpleChanges): void {
     const recreateView = this.shouldRecreateView(changes);
-
     if (recreateView) {
       if (this.viewContainer) {
         this.viewContainer.clear();
diff --git a/components/select/nz-select-top-control.component.ts b/components/select/nz-select-top-control.component.ts
index 1fad6334a66..cd62485f9ef 100644
--- a/components/select/nz-select-top-control.component.ts
+++ b/components/select/nz-select-top-control.component.ts
@@ -63,9 +63,6 @@ export class NzSelectTopControlComponent implements OnInit, OnDestroy {
   }
 
   setInputValue(value: string): void {
-    /* if (this.inputElement) {
-      this.inputElement.nativeElement.value = value;
-    } */
     this.inputValue = value;
     this.updateWidth();
     this.nzSelectService.updateSearchValue(value);
diff --git a/components/select/nz-select.component.ts b/components/select/nz-select.component.ts
index 79c02278e48..3fb4d9b16f6 100644
--- a/components/select/nz-select.component.ts
+++ b/components/select/nz-select.component.ts
@@ -319,6 +319,7 @@ export class NzSelectComponent implements ControlValueAccessor, OnInit, AfterVie
         this.onTouched();
       }
       this.open = value;
+      this.nzSelectService.clearInput();
     });
     this.nzSelectService.check$.pipe(takeUntil(this.destroy$)).subscribe(() => {
       this.cdr.markForCheck();
diff --git a/components/select/nz-select.service.ts b/components/select/nz-select.service.ts
index 9c0dd421619..8c0e82ec718 100644
--- a/components/select/nz-select.service.ts
+++ b/components/select/nz-select.service.ts
@@ -52,11 +52,7 @@ export class NzSelectService {
   searchValue = '';
   isShowNotFound = false;
   // open
-  open$ = this.openRaw$.pipe(
-    distinctUntilChanged(),
-    share(),
-    tap(() => this.clearInput())
-  );
+  open$ = this.openRaw$.pipe(distinctUntilChanged());
   activatedOption: NzOptionComponent | null;
   activatedOption$ = new ReplaySubject<NzOptionComponent | null>(1);
   listOfSelectedValue$ = this.listOfSelectedValueWithEmit$.pipe(map(data => data.value));
@@ -103,7 +99,7 @@ export class NzSelectService {
   // display in top control
   listOfCachedSelectedOption: NzOptionComponent[] = [];
   // selected value or ViewChildren change
-  valueOrOption$ = combineLatest(this.listOfSelectedValue$, this.mapOfTemplateOption$).pipe(
+  valueOrOption$ = combineLatest([this.listOfSelectedValue$, this.mapOfTemplateOption$]).pipe(
     tap(data => {
       this.listOfSelectedValue = data[0];
       this.listOfNzOptionComponent = data[1].listOfNzOptionComponent;