Method for preparing flame-retardant fibers

The invention discloses a method for preparing flame-retardant fibers. The method comprises that: photosensitive polymer solution with flame retardant is uniformly coated on the surfaces of fibers by dipping or spraying, and the coating is solidified under the irradiation of an ultraviolet lamp so that the flame retardant is fixed on the surfaces of the fibers and the fibers are endowed with flame-retardant performance, wherein the temperature of a lamp box is controlled to be between 25 and 125 DEG C, the wavelength of an ultraviolet light source is controlled to be between 280 and 350 nanometers, the power is 150 to 250mW/cm , and the irradiation time is 2 to 15 seconds. Compared with the prior art, the flame-retardant fibers have the advantages of difficult fall, durable flame-retardant property, soft handfeel, wearing comfortableness and the like; and the preparation method has simple process and low cost.