Abstract: A flow model of flow field is formulated for axial compressors under periodic dynamic distortion.The frequency response of the flow field model is analysed.A computer program for problems of various types of periodic dynamic distortion has been written according to the flow field model and the numerical method.The flow fields of a two stage L.P.compressor under inlet total pressure periodic dynamic distortion were simulated.The results of computation and experiments are shown in good agreement either in the amplitude or in phase of total pressure fluctuation.The characteristics of propagation of dynamic distortion through the compressor are analysed,sensitivity of compressor to some frequency is found according to the results of computation.