不允许使用自定义样式按钮，请参阅品牌许可：

It is not allowed to use a custom styled like button, see Brand Permissions:

https://www.facebook.com/brandpermissions/

https://www.facebook.com/brandpermissions/logos.php

您只能使用自定义图形进行共享，但在您的情况下，无论如何也应该使用共享功能（Twitter按钮也可以共享）。
请参阅这里：如何在PHP中使用Facebook Sharer

You can only use a custom graphic for sharing, but in your case it would be more appropriate to use a share function anyway (the Twitter button is also for sharing). See here: How to use Facebook Sharer in PHP

...或使用FB.ui功能的Facebook的JavaScript SDK。但是在这种情况下，您也需要一个应用程序。

...or use the JavaScript SDK of facebook with the FB.ui function. But in that case you would need an app too.