In this article, a numerical model for three-dimensional turbulent flow in the sump of the pump station was presented. A reasonable boundary condition for the flow in the sump with several water intakes at different flow rates was proposed. The finite volume method was employed to solve the governing equations with the body fitted grid generated by the multi-block grid technique. By using the Fluent software, the fluid flow in a model sump of the pump station was calculated. Compared with the experimental result, the numerical result of the example is fairly good.