Abstract: Xupu running water pumping station is a low head pumping station near the Yangtzi River， with a design discharge of 5 m3/s and a maximum head of 3.3 m. Considering its characteristics of its low head and small discharge， the submersible tubular pump is selected in the practice. The pump is reconstructed and installed on the original Xupu regulating sluice soleplate. Its inlet conduit bottom board and the original sluice plate have the same elevation and the hydrological data are unchanged. It should be ensured that when the Yangtze River is at low water level, the water inlet conduit of the water pump is submerged fully and the inlet conduit line is plain sailing. No vortex or other undesirable flow patterns should occur in the flow conduit， and the unit should start normally and operate steadily. In this paper, by adopting three-dimensional numerical simulation， domain parameter setting and three-dimensional turbulent flow simulation, and using the computational fluid dynamics method CFD, numerical simulation of internal flow inlet channel is made and comparison of inlet conduit internal flow and pump flow conditions is carried out, and the hydraulic loss of the inlet conduit in various schemes is analyzed. The analysis results show that the line-type B (having inlet size of 1.1 m×3.4 m and outlet diameter of 1.2 m) is in good inflowing condition, having a small head loss, and meeting the requirements of high pumping efficiency. The results can be used as a reference for the optimal design of inlet type line and for the safe operation of the pumping station.