Large eddy simulation was carried out on the interaction between strong shock wave and supersonic mixing layer in DCR's supersonic combustor. The results show that the incidence of strong shock wave in mixing layer induces acceleration of local mixing layer development, while it blocks mixing in the backward sect because of the saturation of eddy absorbing turbulence kinetic energy of the average flow. The bigger shock wave angle induced by supersonic flow round wedge brings the more intense shock and the more deflected mixing layer. There is larger combustion intensity in the reacting supersonic mixing layer flow field with strong shock wave compared to the one without shock wave.