Aiming at the rotor shaft of the common axis reverse transmission system, the optimization design of the transmission system structure was studied. By response surface optimization method, a response surface optimization model based on the finite element simulation analysis software ANSYS workbench was established. According to the fitted response surface model, the structure optimization design of the inner and outer rotor shafts was carried out. Taking a set of inner and outer rotor shafts as an example, effectiveness of optimization of the rotor shaft structure of a common axis reverse transmission system based on response surface method is verified.