Paraffin wax is one of the main components of investment casting mold, which can be divided into low temperature mold, medium temperature mold and high temperature mold. The melting point of low temperature mold is lower than 60℃, and the mold widely used in our country composed of 50% paraffin wax and 50% stearic acid is a typical representative of low temperature mold. The melting point of medium temperature mold material is from 60℃ to 120℃, which is suitable for making high precision investment mold. The melting point of high temperature mold is higher than 120℃, which has high thermal stability and strength, but the thermal expansion is larger, and the shell is easy to break, so its application in practical production is limited.