A new type of variable section profile was constructed via using the base circle involute and the higher-order curve in the form of power series.In view of the shortcoming that the volume performance is only the optimization target in the current optimization design of variable cross-section profile,and the mechanical performance of the profile is not considered,a multi-objective optimization design method considering the volume performance and mechanical performance was proposed.The compression ratio,an important index in volume performance,and the axial gas force and tangential gas force,which are key indexes of mechanical performancee,were taken as the optimization targets,and the multi-objective optimization was carried out by using genetic algorithm.The results show that after optimization,the two indexesare significantly changed compared with those before optimization,the compression ratio is increased by 11.3%,and the axial gas force and tangential gas force are significantly reduced,especially the tangential gas force is greatly reduced,and the maximum axial force and maximum tangential force are reduced by 2.11% and 22.71% respectively.It shows that the proposed optimization method can obtain variable cross-section profiles with better comprehensive performance.