直接使用XHR就可以了。这个例子取自MDN：

var oReq = new XMLHttpRequest();
oReq.open("GET", "/myfile.png", true);
oReq.responseType = "arraybuffer";

oReq.onload = function(oEvent) {
  var arrayBuffer = oReq.response;

  // if you want to access the bytes:
  var byteArray = new Uint8Array(arrayBuffer);
  // ...

  // If you want to use the image in your DOM:
  var blob = new Blob([arrayBuffer], {type: "image/png"});
  var url = URL.createObjectURL(blob);
  someImageElement.src = url;

  // whatever...
};

oReq.send();

您可以设置 $.ajax 传输来修改此处提到的设置：http : //www.henryalgus.com/reading-binary-files-using-jquery-ajax/

// use this transport for "binary" data type

$.ajaxTransport("+binary", function (options, originalOptions, jqXHR) {
    // check for conditions and support for blob / arraybuffer response type
    if (window.FormData && ((options.dataType && (options.dataType == 'binary')) || (options.data && ((window.ArrayBuffer && options.data instanceof ArrayBuffer) || (window.Blob && options.data instanceof Blob))))) {
        return {
            // create new XMLHttpRequest
            send: function (headers, callback) {
                // setup all variables
                var xhr = new XMLHttpRequest(),
                    url = options.url,
                    type = options.type,
                    async = options.async || true,
                    // blob or arraybuffer. Default is blob
                    dataType = options.responseType || "blob",
                    data = options.data || null,
                    username = options.username || null,
                    password = options.password || null;

                xhr.addEventListener('load', function () {
                    var data = {};
                    data[options.dataType] = xhr.response;
                    // make callback and send data
                    callback(xhr.status, xhr.statusText, data, xhr.getAllResponseHeaders());
                });

                xhr.open(type, url, async, username, password);

                // setup custom headers
                for (var i in headers) {
                    xhr.setRequestHeader(i, headers[i]);
                }

                xhr.responseType = dataType;
                xhr.send(data);
            },
            abort: function () {
                jqXHR.abort();
            }
        };
    }
});

然后让你的ajax调用：

return $.ajax({
    url: url,
    method: 'GET',
    dataType: 'binary',
    processData: 'false',
    responseType: 'arraybuffer',
    headers: { 'X-Requested-With': 'XMLHttpRequest' }
}).then(function (response) {
    var data = new Uint8Array(response);
    //do something with the data
    return data;
}, function (error) {
    alertify.error('There was an error! Error:' + error.name + ':' + error.status)
});

如果必须使用jQuery，可以使用$.ajaxSetup()修改低级设置。

例子：

  // Set up AJAX settings for binary files:
  $.ajaxSetup({
    beforeSend: function (jqXHR, settings) {
      if (settings.dataType === 'binary') {
        settings.xhr().responseType = 'arraybuffer';
      }
    }
  })

  // Make the actual call:
  let result = await $.ajax({
    url: '/api/export/data',
    type: 'GET',
    contentType: 'application/json',
    dataType: 'binary',
    processData: false,
    headers: {
      token: localStorage.token,
    },
  });