Abstract: Hartmann-Sprenger(H-S) tube could make flow oscillated with high frequency and high amplitude under JRG mode. This article made the excited jet by putting H-S tube into the traditional jet device to investigate its effects on the supersonic mixing. The CO2 jet excited under three different frequencies was injected into the Mach 2.5 supersonic flow. The planar laser scattering was used to visualize the instantaneous flow while measuring total pressure and sampling the concentration of CO2 were used to obtain the time averaged results. The results showed that the excited jet improved the depth of jet penetration, and made much more large-scale structures ,so that got better mixing in the supersonic flow with less total pressure loss. Keywords: Excited Jet, Supersonic Mixing, Depth of penetration, The large-scale structure