A kind of gesture recognition algorithm of image processing based on 3D Kinect is proposed. The dynamic gesture recognition algorithm is performed by skeleton images and depth images. At first, two skeleton points which are nearest to hands are choosen from 20 skeleton points in a skeleton image. The process of tracking hands is performed by tracking the positions of the two skeleton points. Then the dynamic gesture recognition process is realized by the change of depths of hands (the distance between a hand and a camera).