Asymmetric thermally induced phase polyvinylidene fluoride hollow fiber membrane and preparation method thereof

The invention relates to the technical field of hollow fiber separation membranes, and aims to solve the problems that a dense separation layer is easily formed when a polyvinylidene fluoride hollow fiber membrane is prepared by a water-soluble diluent system thermally induced phase method in the prior art, and the permeability of the polyvinylidene fluoride hollow fiber membrane is poor. The invention provides an asymmetric thermally induced phase polyvinylidene fluoride hollow fiber membrane and a preparation method thereof, and the polyvinylidene fluoride hollow fiber membrane comprises a middle finger-shaped porous layer, a separation layer located on the first surface of the middle finger-shaped porous layer, and a supporting porous layer located on the second surface of the middle finger-shaped porous layer, the thickness of the finger-shaped porous layer accounts for less than 15% of the total thickness of the membrane layer, and the thickness of the supporting porous layer accounts for more than 85% o