Activity is an important indicator for measuring magnesium oxide used in the rubber industry. Active magnesium oxide is one of the main inorganic active agents, and the small amount in the rubber can greatly improve the degree of sulfidation. Magnesium oxide and zinc oxide mainly play a role in fluidity and oxygen resistance in rubber, and increase the tensile strength and impact resistance of rubber. Magnesium oxide is an important compounding agent for halogen-containing rubber. Magnesium oxide is a vulcanization active agent which has a vulcanization effect at a high temperature and a stabilizer at a low temperature.