The paper summarizes the development of MHD flow control in the world and emphatically introduces three typical experiments: modifying shock wave structure of supersonic inlet; restraining separation of boundary layer; weakening shock wave intensity. The mechanism about MHD flow control is analyzed primarily, i.e. discharge plasma can produce high temperature plasma layer, which will induce new shock wave and become virtual ramp, and thus the former flow filed is changed. The use of applying magnetic field is to control discharge arc direction due to electromagnetic force. Finally, the advantage of MHD flow control is summarized, and according to the comparisons between the foreign and the domestic in research development, the prospect of MHD application and development in aeronautic engineering is performed.