Abstract: In order to process the aviation curvic coupling with annular groove on the domestic CNC spiral bevel gear grindining machine, the machining method of the aviation curvic coupling with annular groove was studied. Based on the machining principle of curvic coupling, the calculation methods of the radius of the grinding wheel, blade point width and the cutter profile radius were provided when the helix angle is not zero. On this basis, an equal section correction was applied to the area of the tooth grooves and teeth on the pitch diameter plane of the aviation curvic coupling with annular groove, and the calculation method of the grinding wheel radius increment was established. Furthermore, a grinding parameters optimization model for curvic coupling was presented, which was based on the Gleason's design criterion of curvic coupling. Grinding parameters optimization design analysis to the curvic coupling was carried out using genetic algorithm. An aviation curvic coupling with annular groove was machined on the domestic H650GA CNC spiral bevel gear grinding machine. The calculation method of the grinding process parameters for the aviation curvic coupling with annular groove was validated by the inspection of practical contact pattern and the inspection of tooth profile error.