To explore the influence of lightweight of hydrodynamic torque converter on its working characteristics and working parts, the hydrodynamic torque converter three-dimensional flow lightweight platform was developed based on the three components hydrodynamic torque converter prototype. By using the Bessel curve, the parameterized modeling of cascade system and the inner and outer ring surfaces was performed to define the thickness coefficients of the blades and the inner and outer rings. Design of experiment method (DOE) was used to establish each wheel with different thickness parameter of single flow channel model, and computational fluid dynamics software was used to calculate the single flow channel model for flow field simulation. The simulation results were used to analyze the unidirectional flow solid interaction calculation of wheels after thickness variation and its influence on the external characteristic and strength. The performance of lightweight torque converter was tested and the results show that with the decrease of thickness, the torque converter can withstand the stress increasing on structure, and the expandance of flow passage and circulatory flux will significantly improve the efficiency and torque values of pump and turbine wheels.