Abstract: Based on the integrated compressible fluid mechanics equations,using eigen value analysis,the new method of non-reflecting boundary condition was proposed for aeroacoustics simulation of disturbance in shear flows.With the new boundary conditions,the disturbance were simulated in static fluid,uniform flows and uniform shear flows,and the results show that the new boundary conditions given in this paper are appropriate.The evolvement of disturbance in compressible mixing layer was also simulated,and the transmitted characteristic of disturbance in compressible mixing layer was presented.