Provided are a virtual fitting device and a virtual fitting method thereof. The virtual fitting method includes acquiring a live video by photographing a user, acquiring a virtual video which includes an avatar corresponding to the user based on a body shape and a movement of the user, determining each composition area of the live video and the virtual video by analyzing the live video and the virtual video, and outputting a virtual fitting video by composing the composition area of the live video and the composition area of the virtual video.