ajax 文件下载，实际上就是模拟表单提交，代码如下：
function download(url, data, method){//url and data options requiredif( url && data ){//data can be string of parameters or array/object data =typeof data ==‘string‘? data : jQuery.param(data);//split params into form inputs var inputs =‘‘; jQuery.each(data.split(‘&‘), function(){ var pair =this.split(‘=‘); inputs+=‘<input type="hidden" name="‘+ pair[0]+‘" value="‘+ pair[1]+‘" />‘;});//send request jQuery(‘<form action="‘+ url +‘" method="‘+(method||‘post‘)+‘">‘+inputs+‘</form>‘).appendTo(‘body‘).submit().remove();};};原文：http://www.cnblogs.com/rongfengliang/p/6690821.html