jS动态的在页面里插入脚本文件

(function() {
  var obj = document.createElement("script");
  obj.type = "text/javascript";
  obj.src = "https://your_script_file.js";
  document.getElementsByTagName("head")[0].appendChild(obj);
} ());

按钮化

<a href='javascript:(function(){var a=document.createElement("script");a.type="text/javascript";a.src="https://your_script_file.js";document.getElementsByTagName("head")[0].appendChild(a)}());'>插入</a>