Nano aluminum oxide has stable crystal phase, high hardness, and good dimensional stability. It can be widely used for strengthening and toughening various plastic, rubber, and ceramic products, especially to improve the density, smoothness, cold and hot fatigue resistance, fracture toughness, creep resistance, and wear resistance of polymer materials. Due to the excellent performance of nano aluminum oxide as a far-infrared emission material, it is applied as a far-infrared emission and insulation material in chemical fiber products and high-pressure sodium lamps. In addition, alpha phase alumina has a high electrical resistivity and good insulation performance, which can be applied in the main accessories of YGA laser crystals and integrated circuit substrates.