function is_mobile(){
    var ua = navigator.userAgent, isMobile = false;
    var ma = ["240x320","acer","acoon","acs-","abacho","ahong","airness","alcatel","amoi","android","anywhereyougo.com","applewebkit/525","applewebkit/532","asus","audio","au-mic","avantogo","becker","benq","bilbo","bird","blackberry","blazer","bleu","cdm-","compal","coolpad","danger","dbtel","dopod","elaine","eric","etouch","fly ","fly_","fly-","go.web","goodaccess","gradiente","grundig","haier","hedy","hitachi","htc","huawei","hutchison","inno","ipad","ipaq","ipod","jbrowser","kddi","kgt","kwc","lenovo","lg ","lg2","lg3","lg4","lg5","lg7","lg8","lg9","lg-","lge-","lge9","longcos","maemo","mercator","meridian","micromax","midp","mini","mitsu","mmm","mmp","mobi","mot-","moto","nec-","netfront","newgen","nexian","nf-browser","nintendo","nitro","nokia","nook","novarra","obigo","palm","panasonic","pantech","philips","phone","pg-","playstation","pocket","pt-","qc-","qtek","rover","sagem","sama","samu","sanyo","samsung","sch-","scooter","sec-","sendo","sgh-","sharp","siemens","sie-","softbank","sony","spice","sprint","spv","symbian","tablet","talkabout","tcl-","teleca","telit","tianyu","tim-","toshiba","tsm","up.browser","utec","utstar","verykool","virgin","vk-","voda","voxtel","vx","wap","wellco","wig browser","wii","windows ce","wireless","xda","xde","zte","GiONEE","GiONEE-"];
    for (var i = 0, lens = ma.length; i < lens; i++) {
        if (ua.indexOf(ma[i]) > -1) {
            isMobile = true;
            break;
        }
    }
    return isMobile;
}
if(is_mobile() === true){
    document.write(navigator.userAgent + '<br>');
    document.write('mobile access!');
    //location.href = "http://blog.hankewins.com/"
} else {
    document.write(navigator.userAgent + '<br>');
    //document.write('pc access!'); 
}

参考:http://levi.cg.am/?p=2214