In order to study the effect of the scale accumulation of the compressor on the blade boundary flow field during operation. This paper takes the 1.5-stage compressor model of the CFM56-7B turbofan engine as the research object, and uses the SST k-ω turbulence model to perform numerical simulation calculations on the transient flow field. By comparing the numerical simulation results, the effects of different blade surface roughness on the velocity in the boundary layer, the thickness of the viscous bottom layer, the coefficient of surface friction resistance, and the wall shear force are analysed. The results show that the equivalent sand model is used to treat the surface roughness of the blade, which has a great influence on the blade leading edge speed. As the surface roughness of the blade increases, the thickness of the boundary layer, the coefficient of frictional resistance of the surface, and the wall shear force all increase. The research results can provide a reference for the cleaning parameters of the compressor.