HongNuan fiber super thermal insulation fiber is an innovative application of metamaterial aerogel in high polymer. It is a polyester composite fiber modified by aerogel. It adopts a structure of fiber evenly wrapping micro nano porous materials, and its thermal conductivity is less than 0.020 (W/(m · K). This technology not only completely breaks the monopoly of foreign countries in the field of polymer thermal insulation, but also has completely independent intellectual property rights in terms of process and equipment. Its sales price is only one-third of similar foreign products, and it has the characteristics of thermal insulation, low cost, excellent performance, long service life, and mass production. Using Hongnuan fiber to make filling cotton can replace down, with lower thermal conductivity and greatly reducing the thickness of winter warm clothing, making it comfortable to wear without appearing bulky; The fabric made of Hongnuan fiber can be used to make lightweight warm clothing, high-temperature work clothes, firefighting clothes, daily warm clothing, etc.