Alumina fiber not only has excellent properties such as high strength and high temperature resistance, but also has good high temperature oxidation resistance, corrosion resistance and electrical insulation. Alumina fiber is mainly used in high-temperature insulation materials and reinforced composite refractory materials, and is widely used in aviation, aerospace, military and high-tech fields. Alumina fiber-reinforced metal matrix and ceramic matrix composites can be used in nozzles and gaskets of supersonic aircraft and rocket engines, and can be used above 2200 °C.