Abstract: In order to study the internal solid-liquid-gas flow of centrifugal pump, Pro/E 3D modeling software was used to make geometric modeling. Based on the application of Reynolds time-average equations, two-equation turbulence model and SIMPLEC algorithm, numerical simulation were involved in studying the flow rules of the solid-liquid-gas flow media in the centrifugal pump. Comparing the calculation results, the solid volume fraction reached the maximum at 0.4 of r/R2, then sharply declined in a straight line, and were fluctuating at certain point; the gas volume fraction was small at 0.2~0.4 of r/R2, and increased sharply after 0.4 of r/R2. Solid and gas phase concentration influenced each other in the particle size distribution. The gas phase mainly gathered in the middle of the blade, which made the vortex appear in the impeller passageway. The energy exchange and transmission in the passageway were influenced the emerging vortex. Without vortex in the passageway, the solid phase moved along the surface of the impeller; and with vortex, it moved with the rotation of the vortex. The flow track was rarely influenced with the increasing of solid phase concentration increases. The research provides a reference for the further research and application of gas-liquid-solid multiphase flow.