The method of the optimization design for gear wheel spoke which is based on CAD model is investigated.The optimal mathematics model including the choice of the design variables

objective function and construction is established.The 2D CAD model data structure and the calculation of related parameters are discussed.Based on the research

the software on the gear wheel spoke optimization was developed.The application research in the gearbox of the helicopter was presented to validate the design method.The weight and Von-Mises stress of the gear are evidently reduced.