Abstract: With Moldflow injection simulation software, based on the analysis of key indicators of the cooling system for injection molding of busbar insulation parts, the cooling system was optimized by adjusting the arrangement of the water path, adding five new cooling water paths and inserting the water partition plate. The cooling time and temperature indices of the optimized cooling system were simulated and analyzed. The results show that after optimization, the circuit coolant temperature, circuit metal temperature and part temperature of the optimized cooling system are obviously reduced, and the cooling time is shortened. The optimized cooling system has ideal cooling effect and the cooling pressure is effectively alleviated.