Hydraulic torque converter optimization design was based on CAD-CFD, this paper analysis the influence factors to the whole performance and optimal design the hydraulic torque converter. Modeling of the hydraulic torque converter was parameterized by using BladeGen at first, the working conditions in different speed ratio were calculated by basing on CFX, statistical performance curves of the hydraulic torque was compared with experiment results. This paper analyzed the characteristics of energy head distribution, and obtained optimal structure by according to flow field, made aerofoil structure in internal and external ring adapt to the working conditions with different speed ratio, the energy head optimization of state working in low speed ration working conditions was achieved, which above increasd the turbine output torque; the maximum increment of turbine output torque at low speed rate working conditions reached to 175.36N·m. After optimization, the hydraulic torque converter torque ratio increased 0.344 with 0 speed ratio working condition,the efficiency increased 2.95% in 0.274 speed ratio working condition.