By taking the new oil pump as research objects, a geometry modeling of the internal flow field in rotor oil pump was made by CAD software. By using the generation of unstructured grid technique, meshes and finite element pre processing of the model were done. Numerical simulation analysis of three-dimensional (3-D) turbulent flow for import and export of rotor oil pump under steady working condition was done by using computer fluid dynamics (CFD) software, based on the turbulent fluid model. The pressure contour line nephogram, flow value and streamline figures, and the relation curve between oil pump volume efficiency and rotational speed were obtained. Then flow test was carried out on the prototype, and the simulation results were fitted with the experiment results quite well, by comparing the relation curve between oil pump volume efficiency and rotational speed from numerical simulation and characteristics curve from experiments. The results prove that the numerical simulation can show precisely the flow characteristics and the special flow performance of oil pump, which provides a new method of research and technical support for oil pump product development and design.