Abstract: The removal of organic pollutants and bacteria is the difficulty of water purification process. Photocatalysis has the advantages of environmental protection, energy saving and high efficiency, flexible photocatalytic materials play an important role in water pollution control. Flexible photocatalytic materials are of great significance in water pollution prevention. Here, a series of polyvinyl alcohol composite chitosan grafted oxygenated graphite carbon nitride (PVA/CS-OCN) nanofiber membranes with different ratios were prepared by electrospinning, and the microstructure, photoelectric performance, photocatalytic performance of PVA/CS-OCN nanofiber membranes were investigated. The average fiber diameter was (137±20.8) nm with a smooth surface and uniform fiber formation. The tensile test results showed that PVA/CS-OCN-3's fracture elongation and tensile strength were about 78.5% and 15.8% higher than those of the PVA membrane. The results of photocurrent test showed that PVA/CS-OCN-3 had higher photocurrent intensity and lower charge transfer resistance. The results showed that the composite grafting and nano modification not only improved the high electron-hole recombination rate of carbon nitride, but also increased the proportion of photoinduced electron production, and the high specific surface area and uniform pore size provided more active sites for the generation of photocatalytic reactions. The inhibition diameter of PVA/CS-OCN-3 reached (19±0.1) mm against E. coli within 24 h under visible light, exhibiting excellent photocatalytic bactericidal ability. The maximum degradation efficiency for methylene blue (MB) at 390 min can reach 72.6%.