The purpose of this paper is to solve shortcomings of low transition Mach number of ramjet, weak anti back pressure ability and less trust. For the study object of a single stage axial compressor blade, optimization design of a three-dimensional blade profile was conducted based on the method consisting of artificial neural network and genetic algorithm. The optimization simulation result shows that isentropic efficiency and overall pressure rate increase, and the optimized compressor as supercharging device places in subsonic section of inlet. The numerical simulation of inlet under two conditions of pressurized device and unpressurized device was conducted. The numerical simulation result shows that aerodynamic performance of the supercharging device is improved obviously, and anti-back pressure ability of the inlet increases, thereby increasing engine thrust.