Docking process occurs in food machinery processing, the accuracy of the docking process can directly affect the later process successfully. In order to solve the problem of low docking accuracy which depends only on the signal sensors, the design method of processing docking platform based on three dimensional image is afforded, by analyzing the influence of three-dimensional image mechanical calibration principle of docking process, and acquiring the feature points in the optimal docking area of a large number of the three dimensional docking images which can be chosen based on local brightness, ratio of contrast, information of structure, the three dimensional images can be restored, and then the child moment of the geometry array of the z axis can be gotten, with the optimal docking information, the high accuracy docking can be realized by used of the the projection matrix. The simulation results show that the proposed method is of high efficiency and with high docking accuracy.