Abstract: The change of the blade shape will result in the performance degradation of compressor.Traditionally,the calculation of the compressor performance degradation is accomplished by assuming that the blade surface varies evenly,or the loss coefficient is introduced into the model,which often produces error.The paper simulated the change of the blade shape caused by fouling using the method of adding random size in the fouling position.Meanwhile,the effect of the ingredients of the blade foul and tip clearance increase on the compressor performance was analyzed.The quantitative performance degradation at different work conditions,and the change of the air float field and the total temperature around the blade surface were gained.The results offer theoretical and applicative value for the research of the engine performance degradation and fault analysis.