是的，这确实很烦人.不使用引导程序也是如此，即使您声明了className，也始终添加.dt-button.您可以使用 init 回调修改示例类:

Yes, this can be really annoying. It is the same without using bootstrap, where .dt-button always is added even if you declare className. There is a init callback you can use to modify for example classes :

$('#example').DataTable( {
  dom: 'Bfrtip',
  buttons: [{
    extend: "excel",
    className: "btn-sm btn-success",
    titleAttr: 'Export in Excel',
    text: 'Excel',
    init: function(api, node, config) {
       $(node).removeClass('btn-default')
    }
  }]
});

演示-> https://jsfiddle.net/m6hysypd/

demo -> https://jsfiddle.net/m6hysypd/

更新:对此已经获得了很多好评，但是正确或*** 答案实际上是"DavidDomains"的答案，以下.使用

Update: Have received a lot of upvotes on this, but the correct or best answer is actually "DavidDomains"'s answer below. Use

buttons: {
  dom: {
    button: {
      className: ''
    }
  },
  buttons: [{
    //here comes your button definitions
  }]
}