正如您在评论中所说，您使用的是模态控制器

As you said in your comment you use a modal controller

在viewWillappear

     UIBarButtonItem *backButton = [[UIBarButtonItem alloc] initWithTitle:@"Back" style: UIBarButtonItemStyleBordered target:self action:@selector(Back)];
     self.navigationItem.leftBarButtonItem = backButton;

在

- (IBAction)Back
  {
    [self dismissViewControllerAnimated:YES completion:nil]; // ios 6
  }