js_fake_touch

        let ele =  document.getElementById('GameCanvas');
        let rect = ele.getBoundingClientRect();
        let touch = new Touch({
            "identifier" : 0,
            "target" : ele,
            "clientX" : (rect.left + rect.right)/2,
            "clientY" : (rect.top + rect.bottom)/2,
            "screenX" : (rect.left + rect.right)/2,
            "screenY" : (rect.top + rect.bottom)/2,
            "pageX" : (rect.left + rect.right)/2,
            "pageY" : (rect.top + rect.bottom)/2,
            "radiusX" : 11.5,
            "radiusY" : 11.5,
            "rotationAngle" : 0.0,
            "force" : 1});

        let touchstart = new TouchEvent("touchstart", {
            cancelable: true,
            bubbles: true,
            composed: true,
            touches: [touch],
            targetTouches: [touch],
            changedTouches: [touch]
        });

        let touchend = new TouchEvent("touchend", {
            cancelable: true,
            bubbles: true,
            composed: true,
            touches: [touch],
            targetTouches: [touch],
            changedTouches: [touch]
        });

        ele.dispatchEvent(touchstart);
        ele.dispatchEvent(touchend);

来源：https://www.cnblogs.com/daihanlong/p/12348362.html