Vacuum casting is a casting process in which metals are melted, poured and crystallized in a vacuum chamber. Vacuum casting can minimize the gas content in the metal and prevent metal oxidation. This method can be used to produce special alloy steel castings with high requirements and titanium alloy castings which are easily oxidized. The cost of vacuum casting is high, and it is generally used for smelting alloys and high-quality castings with high vapor pressure and easy volatilization loss, and the mold should not contain volatiles.