Abstract: In order to explore the best low pressure casting parameters of an aluminum alloy car wheel hub, Taguchi test, signal-to-noise ratio analysis and numerical simulation were used to optimize the pouring temperature, preheating temperature of upper and lower die and filling time with porosity, secondary dendrite arm spacing and solidification time as the optimization objectives. The results show that the casting quality is significantly improved when the pouring temperature is 650 ℃, the preheating temperature of upper die is 280 ℃, the preheating temperature of lower die is 340 ℃ and the filling time is 20 s.