SOURCE

var TxtType = function(el, toRotate, period) {
  this.toRotate = toRotate;
  this.el = el;
  this.loopNum = 0;
  this.period = parseInt(period, 10) || 2000;
  this.txt = '';
  this.tick();
  this.isDeleting = false;
};

TxtType.prototype.tick = function() {
  var i = this.loopNum % this.toRotate.length;
  var fullTxt = this.toRotate[i];

  if (this.isDeleting) {
    this.txt = fullTxt.substring(0, this.txt.length - 1);
  } else {
    this.txt = fullTxt.substring(0, this.txt.length + 1);
  }

  this.el.innerHTML = '<span class="wrap">' + this.txt + '</span>';

  var that = this;
  var delta = 200 - Math.random() * 100;

  if (this.isDeleting) {
    delta /= 2;
  }

  if (!this.isDeleting && this.txt === fullTxt) {
    delta = this.period;
    this.isDeleting = true;
  } else if (this.isDeleting && this.txt === '') {
    this.isDeleting = false;
    this.loopNum++;
    delta = 500;
  }

  setTimeout(function() {
    that.tick();
  },
  delta);
};

window.onload = function() {
  var elements = document.getElementsByClassName('typewrite');
  for (var i = 0; i < elements.length; i++) {
    var toRotate = elements[i].getAttribute('data-type');
    var period = elements[i].getAttribute('data-period');
    if (toRotate) {
      new TxtType(elements[i], JSON.parse(toRotate), period);
    }
  }
  var css = document.createElement("style");
  css.type = "text/css";
  css.innerHTML = ".typewrite > .wrap { border-right: 0.08em solid #fff}";
  document.body.appendChild(css);
};

<h1>
  <a href="http://www.detechn.com/" class="typewrite" data-period="2000"
  data-type='[ "本人擅长Ai、Fw、Fl、Br、Ae、Pr、Id、Ps等软件的安装与卸载", "精通CSS、JavaScript、PHP、ASP、C、C＋＋、C#、Java、Ruby、Perl、Lisp、python、Objective-C、ActionScript、Pascal、spss、sas等单词的拼写", "熟悉Windows、Linux、Mac、Android、IOS、WP8等系统的开关机。"]'>
    <span class="wrap">
    </span>
  </a>
</h1>

body {
  background-color: #ce3635;
  text-align: center;
  color: #fff;
  padding-top: 10em;
}

* {
  color: #fff;
  text-decoration: none;
}