The human center of gravity is the basic parameter reflecting the human body's morphological structure and the quality distribution characteristics. In order to obtain the accurate position of the center of gravity flexibly in a somatosensory interactive equipment environment, this study obtains the human body real-time joint point coordinate data by using the somatosensory interactive device Kinect, and constructs the calculation of the human center of gravity. Combining the multiplicative coefficient method, a real-time linear calculation method to calculate the human center of gravity is proposed. At the same time, in order to verify the accuracy of the center of gravity, this method is tested by the data of the center of gravity provided by the plate pressure test system Footscan as the standard center of gravity data. The results show that the method has similar results in the center of gravity calculation and has better accuracy in the action of large scale.