@property(nonatomic,strong)UIBarButtonItem *mapBtn;//第一个

@property(nonatomic,strong)UIBarButtonItem *messageBtn;//第二个

//第一个
-(UIBarButtonItem *)mapBtn{

    if (!_mapBtn) {

        UIButton *btn  = [UIButton buttonWithType:UIButtonTypeCustom];
        [btn addTarget:self action:@selector(buttonClick:) forControlEvents:UIControlEventTouchUpInside];
        [btn setImage:[UIImage iconWithInfo:TBCityIconInfoMake(@"\U0000e637", 23, __kColorGray)] forState:UIControlStateNormal];
        [btn sizeToFit];
       _mapBtn =  [[UIBarButtonItem alloc] initWithCustomView:btn];
        
    }
    return _mapBtn;
}

//第二个
-(UIBarButtonItem *)messageBtn{

    if (!_messageBtn) {

        UIButton *btn  = [UIButton buttonWithType:UIButtonTypeCustom];
        [btn addTarget:self action:@selector(buttonClick:) forControlEvents:UIControlEventTouchUpInside];
        [btn setImage:[UIImage iconWithInfo:TBCityIconInfoMake(@"\U0000e69a", 25, __kColorGray)] forState:UIControlStateNormal];
        [btn sizeToFit];

         _messageBtn =  [[UIBarButtonItem alloc] initWithCustomView:btn];
        
    }
    return _messageBtn;
}

//显示
- (void)viewDidLoad {
    
    [super viewDidLoad];

//间隙
UIBarButtonItem *fixedSpaceBarButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFixedSpace target:nil action:nil];
    fixedSpaceBarButtonItem.width = 12;
    
    self.navigationItem.rightBarButtonItems = @[self.messageBtn,fixedSpaceBarButtonItem,self.mapBtn];

}

感谢：https://www.jianshu.com/p/f874326c6c44