Ultrathin　Bi2WO6　nanosheets　with　a　high　concentration　of　surface　oxygen　vacancies　(BWO-OVs)　are　successfully　constructed　for　the　degradation　of　levofloxacin　(LVX)　under　visible　light　irradiation　and　show　a　high　degradation　efficiency　of　LVX　(approximate　to　100　%).　It　is　revealed　that　the　oxygen　vacancies　(OVs)　over　BWO-OVs　nanosheets　can　not　only　accelerate　the　separation　of　photo-induced　electrons　and　holes,　but　also　activate　the　O2　molecules　to　form　＇O2-　species.　The　FTIR　spectra　and　density　functional　theory　deeply　demonstrate　that　piperazine　ring　and　C--O　groups　(carboxylic　acid)　in　LVX　can　be　chemisorbed　and　activated　by　surface　Lewis　acid　sites.　The　EPR　results　reveal　that　photo-generated　holes,　＇O2-　and　＇OH　species　are　reactive　oxygen　species　for　the　photocatalytic　degradation　of　LVX.　The　possible　intermediate　is　well　investigated　by　LC-MS　results　combined　with　the　FTIR　spectra　results.　This　work　provides　a　new　perspective　for　understanding　photocatalytic　degradation　from　the　interaction　between　the　active　sites　of　a　photocatalyst　and　antibiotics　molecules.