Burned magnesia brick is made of high purity magnesia. The higher the content of MgO, the higher the sintering temperature, the higher the degree of direct bonding of magnesite crystal, the better the high temperature performance and corrosion resistance of the product. The electrically fused magnesia brick made of electrically fused magnesia as raw material has high density, large crystal size of magnesite, and better high temperature volume stability, high temperature strength, slag resistance strength and slag resistance performance. Magnesium brick is widely used in permanent lining of steelmaking furnaces, limestone kilns, glass kilns, ferro-alloy furnaces, mixed iron furnaces, non-ferrous metal smelting furnaces, etc.