Air　pollution　caused　by　bacteria　and　viruses　has　posed　a　serious　threat　to　public　health.　Commercial　air　purifiers　based　on　dense　fibrous　filters　can　remove　particulate　matter,　including　airborne　pathogens,　but　do　not　kill　them　efficiently.　Here,　we　developed　a　double-grafted　antibacterial　fiber　material　for　the　high-efficiency　capture　and　inactivation　of　airborne　microorganisms.　Tetracarboxyl　phthalocyanine　zinc,　a　photosensitizer,　was　first　grafted　onto　the　polyester　(PET)　fiber,　followed　by　coating　with　chitosan　on　the　surface　of　PET　fiber　to　make　a　double-grafted　fiber　material.　Under　the　irradiation　of　light　with　a　specific　wavelength　(680　nm),　double-grafted　fiber　materials　killed　up　to　99.99%　of　Gram-positive　bacteria　and　Gram-negative　bacteria　and　had　a　significant　antibacterial　effect　on　drug-resistant　bacteria.　The　double-grafted　PET　fiber　showed　broad-spectrum　antibacterial　activities　and　was　capable　to　inactivate　drug-resistant　bacteria.　Notably,　in　filtration　experiments　for　airborne　bacteria,　this　double-grafted　PET　fiber　demonstrated　a　high　bacteria　capture　efficiency　(95.68%)　better　than　the　untreated　PET　fiber　(64.87%).　Besides,　the　double-grafted　PET　fiber　was　capable　of　efficiently　killing　airborne　bacteria.　This　work　provides　a　new　idea　for　the　development　of　air　filtration　materials　that　can　efficiently　kill　airborne　pathogen　and　has　good　biosafety.