Existing simulation processing methods are difficult to obtain the tooth surface that is close to the actual processing. This paper proposes a high-precision simulation processing method for hard tooth surface gearing. Through the establishment of a high-precision cutter and tooth blank geometric model, analysis of the kinematics principle and meshing relationship between the cutter and tooth blank, combined with the functions of rotation, translation and Boolean operation in the 3D software, the high-precision shaping simulation processing of hardened gears is realized. By measuring the normal distance between the standard involute and the gear tooth profile, the tooth surface error analysis is completed. The simulation model is reconstructed, and the models are analyzed by finite element method (FEM) respectively, and the effectiveness of the method in this paper is verified by comparing the analysis results.