<img  src='src' data-name='自定义名称'>
<script>
//js实现图片下载

function download(){

        var name = $('#downImg').attr("data-name");

        var url = $('#downImg').attr("src");

        var a = document.createElement('a')

        var event = new MouseEvent('click')

        a.download = name || '下载图片名称'

        a.href = url

        a.dispatchEvent(event)

}
</script>