In order to study the influence of different impeller inlet width on the performance parameter of centrifugal pump, we utilize the method of CFD simulation, getting the pressure distribution in different condition of impeller inlet width. And then through theoretical calculation, we gain the lift and efficiency under various situations of impeller inlet width and do the analysis and research on them. The results show that when the inlet width of centrifugal pump impeller is 66mm, the comprehensive performance is better. This provides a reference for the design and production of centrifugal pump.