Abstract: The valve is usually used in a multi-phase flow environment, the operating environment is relatively harsh, especially the distribution of the solid-liquid two-phase flow field inside is very complex, making the valve prone to cavitation and erosion wear. In order to solve the above problems and improve the service life of the valve, taking the butterfly valve as an example, the turbulent flow and discrete phase flow model were established by using the finite element analysis software Fluent, and the flow field in the middle channel of the butterfly valve was numerically simulated, and the influence of the opening degree of the valve on the wear of the butterfly valve wall and butterfly plate was analyzed. The results showed that the wear amount and wear range of the butterfly valve increase with the decrease of the opening of the butterfly valve itself. The butterfly plate is the most worn part of the butterfly valve, and the middle part is almost free from wear. By optimizing the structure of the butterfly valve, the wear range of the butterfly valve can be effectively reduced and the stability of the butterfly valve can be improved.