High-purity magnesium oxide at high temperature has excellent alkali resistance and electrical insulation, good light transmission, can often be used as high-temperature heat-resistant materials. In ceramic field, it is used as raw material for translucent ceramic crucible, substrate and so on. The electrical field is used for magnetic device packing, insulation material fillers and various carriers. The thermal conductivity of ceramic substrate is 2 times higher than alumina, and the loss of electrolyte is only 1/10 of alumina. It can also be used as raw material for high-purity fused magnesia, and can be used as an analytical pure Magnesium Oxide in chemistry.