It is a kind of polyurethane elastic fiber with good performance. It not only has good elasticity, but also has such characteristics as fine fiber, high intensity, large-scale elasticity, small specific density and excellent durability. It is a new kind of textile material, which can produce fabrics with the textile fibers of cotton and terylene. It is widely used in such fields as socks, swimwear, underwear, sports garments and western style clothes fabrics.