diff --git a/components/input-number/nz-input-number.component.ts b/components/input-number/nz-input-number.component.ts
index f65e55c61ba..a7cf50fe039 100644
--- a/components/input-number/nz-input-number.component.ts
+++ b/components/input-number/nz-input-number.component.ts
@@ -104,12 +104,10 @@ export class NzInputNumberComponent implements ControlValueAccessor, AfterViewIn
   }
 
   updateAutoFocus(): void {
-    if (this.isInit) {
-      if (this.nzAutoFocus) {
-        this.renderer.setAttribute(this.inputElement.nativeElement, 'autofocus', 'autofocus');
-      } else {
-        this.renderer.removeAttribute(this.inputElement.nativeElement, 'autofocus');
-      }
+    if (this.nzAutoFocus) {
+      this.renderer.setAttribute(this.inputElement.nativeElement, 'autofocus', 'autofocus');
+    } else {
+      this.renderer.removeAttribute(this.inputElement.nativeElement, 'autofocus');
     }
   }
 
@@ -365,5 +363,8 @@ export class NzInputNumberComponent implements ControlValueAccessor, AfterViewIn
 
   ngAfterViewInit(): void {
     this.isInit = true;
+    if (this._autoFocus) {
+      this.focus();
+    }
   }
 }
diff --git a/components/input-number/nz-input-number.spec.ts b/components/input-number/nz-input-number.spec.ts
index 05576fb8470..022bec36a26 100644
--- a/components/input-number/nz-input-number.spec.ts
+++ b/components/input-number/nz-input-number.spec.ts
@@ -1,5 +1,5 @@
 import { Component, ViewChild } from '@angular/core';
-import { fakeAsync, flush, TestBed } from '@angular/core/testing';
+import { fakeAsync, flush, TestBed, tick } from '@angular/core/testing';
 import { FormsModule, FormBuilder, FormGroup, ReactiveFormsModule } from '@angular/forms';
 import { By } from '@angular/platform-browser';
 
@@ -57,7 +57,10 @@ describe('input number', () => {
     it('should autofocus work', () => {
       fixture.detectChanges();
       testComponent.autofocus = true;
+      testComponent.nzInputNumberComponent._autoFocus = true;
+      testComponent.nzInputNumberComponent.ngAfterViewInit();
       fixture.detectChanges();
+      expect(inputElement === document.activeElement).toBe(true);
       expect(inputElement.attributes.getNamedItem('autofocus').name).toBe('autofocus');
       testComponent.autofocus = false;
       fixture.detectChanges();