Abstract: In order to realize wide-speed-range flight of high-speed vehicle, it is of great importance to maintain the performance of inlet at off-design. Compared with traditional passive control methods, plasma and magnetohydrodynaimic(MHD) flow control are novel active flow control methods, and they have attracted extensive attention worldwide, as a result of some advantages, such as simple structure, fast response and feedback control based on actual flight condition, etc. In this paper, the main applications of plasma and MHD in hyper/supersonic inlet and dynamics models are introduced. When the inlets are in supercritical state, the shockwaves can be push back to cowl as a result of the virtual surface produced by plasma and MHD, which is based on the effect of thermal chocking. This technology is expected to applied on the hypersonic missile if only short-time flow control is required. The plasma and MHD actuators can be mounted flush on the wall, so that its requirement for thermal protection is less than that of roughness at hypersonic flight condition. The applications of high-frequency plasma and MHD actuation to produce disturbances in boundary layer have been validated through supersonic wind tunnel experiment, and the physical mechanism can be interpreted from the point of stability theory. The innovative developments of plasma source technology and the way of actuation, as well as coupled model of plasma and fluid dynamics and efficient algorithms are required in future, which can provide guidance for engineering application.