Magnesium alloy is a magnesium based alloy with the addition of other elements. It is characterized by: small density (about 1.8g/cm3), high specific strength, large elastic modulus, good heat dissipation, good shock elimination, bearing the impact load capacity than aluminum alloy, organic matter and alkali erosion resistance function is good. The main alloying elements are aluminum, zinc, manganese, cerium, thorium and a small amount of zirconium or cadmium. At present the most widely used is magnesium aluminum alloy, followed by magnesium manganese alloy and magnesium zinc zirconium alloy. Mainly used in aviation, aerospace, transportation, chemical, rocket and other industries.