Abstract: Using electrospinning technology to compound antibacterial active ingredients with matrix fibers is seen as an effective means to develop new antibacterial materials. To develop new microbial deterioration control materials for grotto cultural heritage, composite polyacrylonitrile (PAN)-nano silver (AgNPs) electrospun fiber membrane was developed by electrospinning technology. The antibacterial effects of the fiber were further evaluated. Spinning stock solution containing silver particles was prepared by PAN mixing with dimethylformamide, adding silver nitrate and tea polyphenols. Then, the nano fiber membrane containing silver particles was prepared by electrostatic spinning technology. By changing the concentration and reaction temperature of PAN, the physical and chemical properties of electrospun fiber membrane, screening the optimal preparation process of electrospun fiber membrane suitable for the prevention and control of grotto cultural heritage microbial deterioration, the antibacterial effect of fibers was verified in the laboratory and outdoors respectively. The results show that the composite fiber membrane prepared with 12wt% PAN content at 80℃ has the advantages of good fiber mechanical properties and high concentration of silver particles, which is the optimal preparation condition of composite PAN-AgNPs electrospun fiber membrane screened in this study. Silver composite nanofiber material has antibacterial effect on Aspergillus niger and Penicillium ap., two microorganisms related to the deterioration of grotto cultural heritage. Significant antibacterial effect under outdoor rock surface conditions has been detected. These results indicate that the composite PAN-AgNPs electrospun fiber membrane prepared in this study has application value for the control of grotto cultural heritage deterioration.