SDIC is also widely used in the bleaching agents of natural and synthetic fibers in the textile industry. The principle of bleaching is to destroy the pigments in natural fibers and synthetic fibers. SDIC can uniformly release hypochlorous acid in aqueous solution. Hypochlorous acid can change some chromogenic groups in the fiber, destroy the original pigment in the fiber through addition reaction with its conjugate bond, and change the wavelength of light absorbed by the fiber, so as to achieve the purpose of bleaching. Compared with the traditional bleach, SDIC has great advantages. The traditional bleach can only be used under the condition of low temperature, because the speed of traditional bleach destroying the molecular structure of fiber will be accelerated under the condition of high temperature, and the strength of fiber will decrease rapidly under its influence. SDIC can still achieve good bleaching effect even at low temperature; In addition, the molecular structure of natural fiber and synthetic fiber is destroyed slowly by SDIC, the bleaching effect is good, and the strength of fiber will not be greatly affected. In addition, adding SDIC to bleach can also improve the hydrophilicity of clothes, remove cotton pulp from clothes, reduce the degradation rate of cellulose, and improve the flexibility and ductility of clothes.