Three-dimensional simulation was performed for the solid-liquid two-phase turbulent flow in centrifugal pumps with particle model and inhomogeneous model separately by ANSYS-CFX software. k-ε turbulence model was applied to predict the liquid-phase, and an algebraic equation known as the dispersed phase zero equation was adopted to predict the solid-phase. All wall boundaries were set as free slip wall conditions. Under the fraction volume of 0.1, the effect of the different diameters (0.1mm，0.25mm，0.5mm and 0.75mm) of solid particles on the slip velocity on the wall of flow-passage parts was studied. The results show that the slip velocity of solid particles increases along with the increase of the particle diameter. And solid particles gradually accumulate near the wall of press surface. There are three places where slip velocity of solid particles is larger and erosion of wall is more serious, such as the head of blade and the blade trailing edge, also the shroud part close to the back pressure side of blade.