▎ 摘　　要

NOVELTY - A modified polyvinylidene fluoride ultrafiltration membrane preparing method involves freeze-drying a 0.05-4 mg/ml graphene oxide solution to prepare a powder and baking the powder in a high furnace at 150 degrees C for 2 hours to prepare a nitrogen-oxygenated graphene. The mixture is dispersed in an organic solvent to obtain a nitrogen-oxygenated graphene dispersion. Membrane material and additive are added to the nitrogen-oxygenated graphene dispersion, heated at 50-80 degrees C and mechanically stirred for 24 hours to obtain a casting solution. The casting solution liquid is scraped using a doctor blade on a support to form a solution film. The support and the solution film mixture is immersed in a coagulation bath at 30-50 degrees C and the polymer in the solution is precipitated and solidified to obtain the finished product, where the material is film material, nitrogen-oxygenated graphene, additive and organic solvent in a mass ratio of 10-25:0.025-0.5:0-2:70-85. USE - Method for preparing modified polyvinylidene fluoride ultrafiltration membrane. ADVANTAGE - The method enables preparing modified polyvinylidene fluoride ultrafiltration membrane with increased performance, strength, flux and separation precision, in simple and convenient manner.