The temperature distribution of parts and mould was simulated by ANSYS/LS—DYNA. The shortcomings of the uniform waterway were analyzed. APDL was applied over the thermal field simulation. Zero-order search and fist-order search was combined as the optimization algorithm. In this program, the radius of holes, the distances of adjacent holes and the distances of holes and the profile were chosen as optimization variables. The well-distributed temperature of parts and the needed critical cooling rate were chosen as the optimization objectives to create the objective function. Objective function value was 26.553 after the optimization which was 64.404 before the optimization. By comparing the temperature distribution of the optimized cooling water channel with original, it can be seen that the maximum temperature was decreased by 44.5% and the lowest temperature was decreased by 14.5%, to realize the optimization design of parameters of the cooling water channel. Finally the experiment had been designed to verify the correctness of the optimization result.