The recent outbreak of a coronavirus disease (COVID-19) has posed a great threat to public health and financial system . Most current masks used to prevent the spread of COVID-19 are typically absence of biocidal properties . We designed a novel polymer, polystyrene grafted by 5, 5-dimethylhydantoin and trimethylamine (PSDT), which possesses halamine site and cationic quaternary ammonia salt site . Furthermore, PSDT/PU nanofiber @ net membranes (PSDT/PU NNMs) were obtained by electrospinning technology . Our strategy enables inherent N-halamine and quaternary ammonia salt (QAS) group to be covalently integrated into membranes, realizing the efficient and stable biocidal properties . Meanwhile, the introduction of nanonets endows electrospun membranes with prominent air filtration performance . The resulting membranes exhibit integrated properties of high interception of fine particles (96.7 %) and low pressure drop (95.4 Pa). Besides, chlorinated PSDT/PU nanofiber @ net membranes (with active chlorine content of 0.60 wt% and quaternary ammonia salt content of 2.20 wt %) exhibited superior bactericidal (> 99.9999 %) and virucidal (> 99.999 %) efficiency in a short time (2 min), which enables chlorinated PSDT/PU NNMs to be served as the filtration material by providing bacterial interception (99.77 %) and contact killing against pathogens . The successful synthesis of PSDT/PU NNMs provide innovative insights for exploring filtration materials in a nanonet and biocidal form.