Hongnuan fiber super thermal insulation fiber is an innovative application of metamaterial aerogel in polymers. It is an aerogel-modified polyester composite fiber. It uses a structure in which the fiber evenly wraps micro-nano porous materials. The thermal conductivity is lower than 0.020 (W/(m·K). This technology not only completely breaks the foreign monopoly in the field of polymer thermal insulation, but also has completely independent intellectual property rights from process to equipment, and the sales price is only one-third of similar foreign products. First , it has the characteristics of heat insulation and cold protection, low cost, excellent performance, long service life, and can be mass-produced. Filling cotton made of Hongnuan fiber can replace down. It has a lower thermal conductivity and greatly reduces the thickness of warm clothing in winter, making it easier to wear. Comfortable and not bloated; fabrics made of Hongnan fiber can be used to make light thermal clothing, high-temperature work clothing, firefighting clothing, daily warm clothing, etc.