SOURCE

function closewin() {
    var ua = window.navigator.userAgent;

    if (ua.indexOf('iPhone ') > 0) {
        document.querySelector('#button').addEventListener('click', function (event) {
            alert('a');
            try {
                event.preventDefault();
                window.close();
            } catch (ex) {
                alert(ex);
            }
        }, false);

        document.querySelector('#button').click();
    }
}

<div>iPad关闭测试</div>
<a onclick="closewin()">关闭</a>
<input id="button" name="button" type="submit" value="Close">