Abstract: Solid particles have a strong erosion effect on the cyclone separatorin gas-solid separation, and excessive use of time creates cracks. With the aid of computational fluid dynamics Fluent 15.0 software, the distribution law of velocity and pressure of cyclone separator was found by numerical simulation. The erosion effect of solid particles on cyclone separator, as well as the effect of erosion crack on the efficiency of separation was analyzed. The results showed that the solid particles will corrode the top of the cylinder and the bottom of the cone; when cracks occur at the top, separation efficiency decreased from 92.86% to 71.43%; when cracks occur at the bottom, the separation efficiency dropped to 63.10%.The simulation results provided a basis for the optimization of the interior structure of the cyclone separator.