Thermal cycling of die casting die for aluminum alloy speed governor cover was simulated by the ProCAST software.The simulated results indicate that temperature in the die during steady operation stage and temperature during castings-picked out exhibit higher.Cycling parameters were optimized from 60 s per cycling period to 80 s per cycling period by thermal cycling simulation.It is found that the maximum temperature in the die during steady operation stage is decreased from 340℃ to below 300℃

decreased by approximately 20℃ in average temperature

and both die operation temperature and castings-picked-out temperature are decreased to a desirable temperature range.The simulated results are well in agreement with practical ones.