Abstract: Based on constant shock intensity method,a two-dimensional mixed-compression supersonic inlet was designed for flight at Mach number of 3.0.The correction was made for the effects of boundary layer.Quasi-one-dimensional analysis shows that the designed inlet has a good performance.By two-dimensional viscous simulation of inlet flows with terminal shocks,flow status of complicated flow field was presented in two-dimensional mixed-compression supersonic inlet.The reflections and intersections of various shock waves inside the inlet and the separation flows induced by shock wave/boundary layer interaction were displayed reasonably.Boundary layer bleed was considered to minimize separation and provide uniform flow at the engine-face station.Starting characteristic was obtained through numerical simulation under various outflow back pressure.Calculations with bleed indicate that boundary layer bleed can be used to stabilize the terminal shock location and prevent choking of the inlet,which is beneficial to resist outflow back pressure.The presented method is applicable to preliminary inlet design and numerical simulation.