1.

   // 兩秒後模擬點選
setTimeout(function() {
    // IE
    if(document.all) {
        document.getElementById("desc1").click();
    }
    // 其它瀏覽器
    else {
        var e = document.createEvent("MouseEvents");
        e.initEvent("click", true, true);
        document.getElementById("desc1").dispatchEvent(e);
    }
}, 1000);
 

desc1為元素的id，額外寫上點選這個id會觸發的事件。1s後就會執行

2.模擬點選下載檔案、圖片

var url = 'http://192.168.10.133/www/xunzhanMob/logo.jpg';
	      var a = document.createElement('a');
	      console.log(a)
	      var event = new MouseEvent('click');
	      a.download = '';
	      a.href = url;
	      a.dispatchEvent(event);