The internal flow field in stator of a torque converter was simulated. Based on the mixing-plane technology, using the method of CFD(Computational Fluid Dynamics) simulated the stator flow field. The flow field characteristic, the distribution of velocity and pressure in the stator were analyzed. The external performance of the torque converter was also calculated, and the results were compared with the experimental data. It was proved that the calculated results showed agreement with the experiment accurately.