var audio=new Audio("music/music.mp3");
audio.preload="preload";
// 自动播放解决苹果不兼容autoplay属性
audio.loop=true;
audio.play();
document.addEventListener("WeixinJSBridgeReady", function () {
audio.play();
}, false);
https://segmentfault.com/q/1010000006986594?_ea=1201957