The article considers a new technology of magnesium alloy vacuumization during high-pressure casting. For its creation, the technology of casting magnesium radiators in machines with hot chamber high-pressure pressing was taken as a basic one. Magnesium alloys have high characteristics, one of the main ones being their high thermal conductivity, making them ideal for creating efficient radiators compared to traditional aluminum radiators. However, magnesium’s problems, especially its low corrosion resistance, prevent it from being used for such castings. Therefore, improvements in vacuum technology allow the AZ91D magnesium alloy radiator to solve the problems with its corrosion resistance and achieve higher performance than the basic version. Its uniqueness lies in the use of labyrinth air suction from the mold. This solution prevents magnesium from evaporating during vacuuming. Experimental studies demonstrate the high efficiency of the proposed technology, opening new perspectives for mass production. It should also be noted that this vacuumization technology is used as one of the stages of a larger-scale technology of pulsed supply of shielding gases. The combination of these systems allowed to achieve new successes in casting magnesium alloys.