a标签添加download即可下载
<a href="下载地址" download="下载名称">名称</a>a标签下载跨域文件
<a @click="downloadFile(fileUrl,fileName)">下载文件</a>
downloadFile(url, fileName) {
    var x = new XMLHttpRequest();
    x.open("GET", url, true);
    x.responseType = 'blob';
    x.onload=function(e) {
        var url = window.URL.createObjectURL(x.response)
        var a = document.createElement('a');
        a.href = url
        a.download = fileName;
        a.click()
    }
    x.send();
},