Most of solutions kills the original style of BackButton (The left arrowed bar button) while adding a usual button with desired title. So to keep the original style there are 2 ways: 1st: To use undocumented button style (110 or something like that) which I prefer not to do. But if you want you could find how to do it here, on stackoverflow. 2nd: To use I the Trenskow's idea. I liked it and I use it a bit changed. Instead of overriding - (NSString*)title I've decided to keep the original title in the following way (which allows me to use nib's titles as well as given title at push state btw).

- (void)viewDidLoad {
    [super viewDidLoad];
    static NSString * backButtonTitle=@"Back"; //or whatever u want

    if (![self.title isEqualToString:backButtonTitle]){

        UILabel* customTitleView = [[UILabel alloc] initWithFrame:CGRectZero];
        customTitleView.text = self.title; // original title
        customTitleView.font = [UIFont boldSystemFontOfSize:20];
        customTitleView.backgroundColor = [UIColor clearColor];
        customTitleView.textColor = [UIColor whiteColor];
        customTitleView.shadowColor = [UIColor colorWithRed:0.0 green:0.0 blue:0.0 alpha:0.5];
        customTitleView.shadowOffset = CGSizeMake(0, -1);

        [customTitleView sizeToFit];

        self.navigationItem.titleView = [customTitleView autorelease];
        self.title = backButtonTitle; 
    }
}

这个解决方案效果很好，看起来很自然。此外，如果在viewDidLoad方法中使用它，它可以防止执行超过1次。 我也试过杰塞德克的解决方案，但看起来很糟糕。它导致可见的用户标题栏的变化，从原来的BackButton的期望和回来。

这应该放在调用名为NewTitle的ViewController的方法中。 就在push或popViewController语句之前。

UIBarButtonItem *newBackButton = 
        [[UIBarButtonItem alloc] initWithTitle:@"NewTitle" 
                                         style:UIBarButtonItemStyleBordered 
                                        target:nil 
                                        action:nil];
[[self navigationItem] setBackBarButtonItem:newBackButton];
[newBackButton release];

这段代码也可以工作。把这个放到导航控制器的根控制器上:

self.navigationItem.backBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"" style:UIBarButtonItemStylePlain target:nil action:nil];

问题:导航栏中的“返回”文本不能被替换。

原因:在推送视图后，导航栏中设置了“Back”标签，因为父视图控制器中的.title属性被设置为nil(或未初始化)。

一个解决方案:如果你设置self.title="Whatever…"，你会看到在按下新的视图控制器后，"Back"将出现"Whatever…"。

如果你不仅想将后退按钮的文本更改为相同的文本并保持原来的左箭头形状，而且还想在用户单击后退按钮时做一些事情，我建议你看看我的“CustomNavigationController”。

在Swift/iOS8中，以下方法对我来说是有效的:

let backButton = UIBarButtonItem(
      title: "Back Button Text",
      style: UIBarButtonItemStyle.Bordered,
      target: nil,
      action: nil
);

self.navigationController.navigationBar.topItem.backBarButtonItem = backButton;

从斐利贝的回答转过来。