The engine and hydraulic torque converter matching quality directly affects the use of the vehicle performance. For loader matching of engine and hydraulic torque converter, its input and output characteristics were analyzed, and its working parameters were numerically analyzed. On this basis, with the effective diameter of circular circle of hydraulic torque converter as design variables of optimization design, the genetic algorithm was used to optimize the matching of engine and hydraulic torque converter design. The optimization results show that the optimized hydraulic torque converter of effective of the diameter of the circle is up from 0395 to 0428, in full power match and part of the power turbine, effective power is increased by 23% and 65%, respectively, and a 23% increase over the maximum torque at startup. Thus it can be seen through the optimization design can improve the dynamic performance of the loader, and for design of the loader, manufacture and use have important significance.