Method for continuously preparing polyvinylidene fluoride hollow fiber membrane

The invention discloses a method for continuously preparing a polyvinylidene fluoride hollow fiber membrane. The method comprises the following steps: uniformly mixing polyvinylidene fluoride, a composite additive and a pore-forming agent to obtain a membrane-forming system; quantitatively extruding and granulating the membrane forming system through a double-screw extruder, carrying out melt spinning, and drawing a spinning melt cooled to a certain temperature into a constant-temperature stretcher for continuous stretching to obtain a primary hollow fiber membrane; and oscillating and cleaning the primary hollow fiber membrane in water to remove the water-soluble macromolecular pore-forming agent to obtain the PVDF hollow fiber membrane. According to the method, the membrane is prepared by adopting a melt spinning continuous stretching method, multiple interface holes are generated through stretching by utilizing the characteristic that the compatibility of polyvinylidene fluoride and a composite additive is