▎ 摘　　要

NOVELTY - Method for preparing modified hollow fiber membrane involves (a) dissolving polyacrylonitrile in solvent (A) to obtain spinning stock solution (A), mixing graphene with sodium alginate, dissolving in solvent (B), allowing the mixture to stand under static temperature, and reacting to obtain spinning stock solution (B), and (b) using tetraisocyanate, adding coagulant, reacting mixture, extruding e.g. spinning stock solution (B) from the inside of the spinning device, and washing and drying the hollow fiber ultrafiltration membrane. USE - The method is useful for preparing modified hollow fiber membrane (claimed). ADVANTAGE - The prepared modified hollow fiber membrane has improved tensile strength. DETAILED DESCRIPTION - Method for preparing modified hollow fiber membrane involves (a) dissolving polyacrylonitrile having molecular weight of 40000-80000 in solvent (A) to obtain spinning stock solution (A), uniformly mixing graphene with sodium alginate, dissolving in solvent (B), allowing the mixture to stand under static temperature at room temperature, and reacting for 1-3 hours to obtain spinning stock solution (B), where polyacrylonitrile, graphene, sodium alginate, solvent (A), and solvent (B) are in a ratio of 15-30 wt.%, 5-20 wt.%, 10-25 wt.%, 25-50 wt.%, and 15-45 wt.%, and (b) using 1-5 wt.% tetraisocyanate as pore-forming agent, adding 20-50 %mass internal coagulant, reacting the mixture at 35-70 degrees C, using external coagulant, extruding spinning stock solution (B) from the inside of the spinning device, and spinning stock solution (C) from the outside of the spinning device, where the spinning temperature is 23 plus minus 1 degrees C, air temperature is 35 plus minus 1 degrees C, and humidity is 30 plus minus 1 degrees C to obtain hollow fiber membrane, washing the hollow fiber ultrafiltration membrane using organic solvent for 20-30 hours, and then drying the washed hollow fiber ultrafiltration membrane.