By comparing with the experimental data of PAV-15 designed by German space agency

the calculation method of flow field in supersonic cascade with high accuracy was determined. The results showed that the consistency between the calculation and the experimental results can be improved by adjusting the thickness of the flow tube according to the position of shock wave. In order to improve the stability margin and ensure the performance at design point of supersonic cascade

the back pressure estimation method and optimization design method based on target margin were established. The multi-objective optimization of the two supersonic blades was carried out. The optimization results show that the optimal cascade can reduce the incident angle of the shock wave at design point

and cut down the shock wave and shock wave boundary layer interference loss. The aerodynamic throat moving forward and the terminal normal shock wave moving backward can improve the shock-holding capability. Under the premise of keeping the total and static pressure ratio unchanged

the stability margins of the two optimal blade profile reached the design goal

and the loss at design point also decreased.