▎ 摘　　要

NOVELTY - Preparing photocatalytic composite film involves polymerizing amphoteric polyamine monomer molecule with dopamine to obtain polyamine monomer, mixing graphene oxide solution with tetrabutyl titanate and hydrothermally obtaining graphene oxide-titanium dioxide material, mixing graphene oxide-titanium dioxide material, polyamine monomer, and solvent, and then mixing with polyimide polymer solution to obtain mixed solution. The mixed solution is poured onto dry plate, and solvent is removed to obtain photocatalytic composite film. USE - Method for preparing photocatalytic composite film used in field of gas purification, and is preferably one or combination of two of particulate pollutants, gas pollutants, and bacterial microorganisms in the gas (claimed). ADVANTAGE - The method enables to prepare photocatalytic composite film that has characteristics of photocatalytic performance and membrane separation technology, increases specific surface area of the photocatalyst, improves light utilization rate, and realizes gas pollutant separation and catalytic degradation to achieve gas purification.