Abstract: A flow control method using multiple micro-vane vortex generators is proposed to improve the fullness of boundary layer profiles over the forebody ramp of hypersonic vehicles and to reduce the potential risk of flow separation in the inlet. The flowfield characteristics and mixing mechanism at an incoming Mach number of 7.0 are numerically analyzed. The effect of the installation angle of vortex generators on the flowfield is studied as well. Results show that micro-vane vortex generators can generate a local large-sideslip-angle and low-pressure flow in the near-wall region. At the lateral sides of mocro vanes, glancing shocks and expansion waves are generated, which induce the lateral mixing of low-momentum fluid with the mainstream. When installation angles are positive, with the increase of installation angle, the mixing effect gets stronger but the pressure loss increases. Micro vanes with negative installation angles lead to the strongest mixing effect, however, they also bring significant total pressure loss. Compared with the one without flow control, the shape factor of the boundary layer gets smaller by using vortex generators, among which those with an installation angle of 15 degrees lead to the smallest shape factor and consequently the fullest boundary layer profile, which has better anti-separation capability under reverse pressure gradients.