Considering the limit of equipment technology of Low Pressure Casting (LPC) to shape the large magnesium alloy components, an improved LPC equipment technology, including equipment mechanical part, control system and protective gaseous mixture system has been developed. The melting capacity of 1000 kg of molten magnesium and the maximum weight of 850 kg of the unit casting piece were realized. The protective gaseous mixture system with a good ignition-proof effect can mix SF6, CO2 and compressed air in a certain proportion. The Fuzzy-PID hybrid control technology and the digital assemble valves have been applied in the control system to obtain a high pressure control precision