Flap optical fiber composite spinning preparation method

The invention relates to a process for preparing composite spinning of a valvular fiber, which comprises that high refractive index components are fed into a screw (A), low refractive index components are fed into a screw (B), the high refractive index components and the low refractive index components are respectively melted through the screws and reach to a same of spinning pack, spinneret holes commonly enter spinning guide holes, and a fiber is extruded, and then the fiber is cooled through a water bath cooling system and is winded. Sections of the two groups of components of the valvularfiber which is prepared by the invention are formed with a designed valvular fiber section shape, the two components mutually contact and are not separated, and the length of the obtained fiber is capable of being illimitably prolonged. The valvular fiber which is prepared by a composite spinning method is uniformly continuous, and the joint loss is avoided during connecting the fiber.