The design method of torque converter blade based on quadratic function distribution of momentum was put forward. The torque converters have been designed by using both new and traditional methods. The 3-D model of torque converter was established and the flow section area was calculated. Compared with the traditional method, not only the blade profile of new method was more reasonable under equal blade thickening, but also the change of flow section area was more gently. The flow field of torque converters has been numerical simulated by CFD software. Based on the flow numerical solution, the performances of torque converters designed by new and traditional methods have been predicted. The comparison and analysis of the results have been carried out.