Abstract: Based on the computational fluid dynamics analysis software FLUENT, using RNG k-ε turbulence model and SIMPLEC algorithm, numerical simulation of the internal flow field in an axial flow pump is conducted, and analysis is performed for the axial flow pump in low flow rate condition, the design conditions and the large flow rate condition inside the impeller of the distribution of velocity and pressure, and the characteristics of the pump, the axial flow pump lift and efficiency as the flow changes. The research results are helpful for the analysis of axial flow pump internal flow mechanism, and provide important reference for pump hydraulic design.