The invention discloses a regenerable antibacterial nano fiber membrane and a preparation method thereof and belongs to the technical field of medical textile materials. The regenerable antibacterialnano fiber membrane comprises a base cloth layer, a nano fiber membrane layer and a regenerable antibacterial layer are arranged sequentially above the base layer, the nano fiber membrane layer is composed of polyethylene-polyvinyl alcohol nanofiber, and the regenerable antibacterial layer is composed of a composite of poly(2-dimethylaminoethyl methacrylate) molecules and copper ions. The composite of poly(2-dimethylaminoethyl methacrylate) molecules and copper ions is grafted to the polyethylene-polyvinyl alcohol nano fiber, and the prepared regenerable antibacterial nano fiber membrane can block Staphylococcus aureus, Escherichia coli and Candida albicans under the capacity of up to 100%, has antibacterial rate of higher than 98% for the bacteria, is highly comfortable and is widely applicable to the safeguard fields such as medical application.