The fused magnesia is mainly the migration rule of impurities such as Si, Al, Ca, Fe and the influence of melting temperature on the crystallization process of MgO. Finally, it is pointed out that automated, intelligent and energy-saving high-temperature arc furnace production equipment will be the focus of future research and development. The preparation of high-purity magnesium hydroxide using salt lake brine as an intermediate and the preparation of high-purity fused magnesia are the mainstream directions for future development. Fused magnesite is an important industrial raw material. Its production process is simple. It mainly uses magnesite as raw material and is prepared by arc furnace melting method. The research results of China's fused magnesia preparation technology. Ordinary fused magnesia products are mainly made by using magnesite or light-burned magnesite with a content of 47% or more as the main raw material to melt in the arc at high temperature. The periclase has large grains, dense structure, strong slag resistance, and excellent volume stability at high temperatures. Magnesia is mainly used as a good raw material for advanced alkaline bricks, carbon-containing products and unshaped refractory materials.