代码

html

<button type="button" id="btn1">下载一个zip（方法1）</button>
<button type="button" id="btn2">下载一个zip（方法2）</button>
	

js

var $eleBtn1 = $("#btn1");
var $eleBtn2 = $("#btn2");

//已知一个下载文件的后端接口：
https://codeload.github.com/douban/douban-client/legacy.zip/master
//方法一：window.open()
$eleBtn1.click(function(){
	var url = "https://codeload.github.com/douban/douban-client/legacy.zip/master";
	window.open(url);
});

//方法二：通过form
$eleBtn2.click(function(){
	var $eleForm = $("<form method='get'></form>");

	$eleForm.attr("action","https://codeload.github.com/douban/douban-client/legacy.zip/master");

	$(document.body).append($eleForm);

	//提交表单，实现下载
	$eleForm.submit();
});