1. An apparatus for hand gesture recognition based on a depth image, comprising: a depth image acquiring unit configured to acquire a depth image including a hand region; a depth point classifying unit configured to classify depth points of the hand region in the depth image according to a corresponding hand portion by means of a machine studying method; and a hand model matching unit configured to match a three-dimensional hand model with the classified depth points by using distances between the classified depth points and a hand portion respectively corresponding to the depth points.