The research and production of special fibers began in 1950s, and fluorine-containing fibers were put into industrial production for the first time. With the development of aerospace and national defense industry, various aromatic heterocyclic organic high-temperature resistant fibers appeared in the 1960s, such as poly (p-phenylene terephthalamide) fiber, and inorganic high-strength and high-modulus fibers such as carbon fiber and boron fiber. Later, organic flame retardant fibers, such as phenolic fibers, were developed. In 1970s, due to the need of environmental protection and energy saving, high strength and high modulus fibers and various functional fibers were widely used.