[weixinbtn setImageEdgeInsets:UIEdgeInsetsMake(0, 0, 0, 10)];分別上向下、右、上、左偏移~~~~

//微信登入
    UIButton *weixinbtn = [UIButton buttonWithType:UIButtonTypeSystem];
    weixinbtn.layer.cornerRadius = 5;
    weixinbtn.clipsToBounds = YES;
    [weixinbtn setTitle:@"微信登入" forState:UIControlStateNormal];
    [weixinbtn set
 
TitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
    [weixinbtn setImage:[[UIImage imageNamed:@"weixin"]imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal ] forState:UIControlStateNormal];
    [weixinbtn setImageEdgeInsets:UIEdgeInsetsMake(0, 0, 0, 10)];
    [weixinbtn setTitleEdgeInsets:UIEdgeInsetsMake(0
 
, 10, 0, 0)];
    weixinbtn.backgroundColor = [UIColor colorWithHexString:@"73D7BF"];
    [self addSubview:weixinbtn];