I found the solution !
Step1: Add webvr-polyfill into your project.
<script src="./libs/webvr-polyfill.js"></script>
<script src="./libs/playcanvas.js"></script>
Step2: Create VrManager.
var canvas = document.getElementById('application');
var app = new pc.Application(canvas, { });
app.vr = new pc.VrManager(app); // add this line
app.start();
Step 3: Call camera.enterVr
or camera.exitVr
by your self.
That’s it !