Cerium oxide (CeO2) has attracted much attention in recent years owing to its reversible switch ability in Ce3+/Ce4+ redox to produce improved antioxidation properties for biomedical applications. Here, we report to embed the CeO2 nanospheres into the organic polymer network using electrostatic spinning technology to prepare polyvinyl alcohol (PVA)-encapsulated CeO2 nanospheres composite nanofibrous membranes (PVA-CeO2) for the first time, which is beneficial to improving the dispersion and biocompatibility of CeO2 nanosphere without altering the original antioxidant properties of CeO2. Detailed characterization of the as-prepared composite nanofibrous membranes reveals that CeO2 was successfully introduced into the PVA fibers with strong interactions, thus enhancing the thermal stability and fracture toughness of the nanofibers. As a result, PVA-CeO2 exhibits superior UV shielding performance, antioxidant performance and bacteriostatic performance. Meaningfully, PVA-CeO2 has strong absorbance in both UVA and UVB bands when the CeO2 concentration in the nanofiber membrane reaches 1.5 wt%, and shows an excellent scavenging effect on the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals with a scavenging rate of 86.52%. Moreover, the Kirby-Bauer (K-B) method of agar diffusion test further confirms that PVA-CeO2 has antimicrobial ability against three types of representative strains, including Gram-positive bacteria (Staphylococcus aureus), Gram-negative bacteria (Escherichia coli) and fungi (Candida albicans). Importantly, no obvious cytotoxicity is observed for PVA-CeO2 even though the amount of embedded CeO2 nanosphere reaches as high as 1.5 wt%. This study reveals new avenues for improving the future smart design of CeO2-based nanofiber membrane composite materials for biological antioxidants.