It looks like a french braid but it's so much more! Here is how to recreate it:

Take two fairly big chunks of hair from either above or right behind your ears, cross one over the other on the back of your head and bobby pin in place.
Get a couple of sections right below where your previous ones came from, cross them and bobby pin in place.
You will probably have to do this only two or three times, when you reach the end wrap the last two strands you had around all of your hair, bobby pin them and for extra security you can add a clear elastic and hide it under those last two strands you had to wrap around.