The special feature of oxygen filling die casting eliminates or reduces the air holes inside the die casting, and improves the quality of the die casting. The strength of aluminum alloy die castings after oxygen filling is 0% higher than that of normal die castings, and the elongation is 0.5~1 times higher. 2) The oxygen-filled die-casting can be heat treated. The oxygen-filled die-casting can be carried out in the environment of 200~320 ℃. 4) The oxygen-filled die-casting has little burning loss on the aluminum alloy composition. 5) Compared with vacuum die casting, oxygen-filled die casting has simple structure, convenient operation and less investment