Water　eutrophication　leads　to　increasingly　serious　harmful　algal　blooms　(HABs),　which　poses　tremendous　threats　on　aquatic　environment　and　human　health.　In　this　work,　a　novel　magnetically　separable　ZnFe2O4/Ag3PO4/g-C3N4　(ZFO/AP/CN)　photocatalyst　with　double　Z-scheme　was　constructed　for　Microcystis　aeruginosa　(M.　aeruginosa)　inactivation　and　Microcystin-LR　(MC-LR)　degradation　under　visible　light.　The　photocatalyst　was　characterized　by　XRD,　SEM,　EDS,　TEM,　XPS,　FTIR,　UV-vis,　PL,　and　VSM.　Approximately　96.33%　of　chlorophyll　a　was　degraded　by　ZFO/AP/CN　(100　mg/L)　after　3　h　of　visible　light　irradiation.　During　the　photocatalytic　process,　the　malondialdehyde　(MDA)　of　M.　aeruginosa　increased,　the　activities　of　superoxide　dismutase　(SOD)　and　catalase　(CAT)　increased　initially　and　decreased　afterwards.　Furthermore,　the　photocatalytic　removal　efficiency　of　M.　aeruginosa　(OD680　approximate　to　0.732)　and　MC-LR　(0.2　mg/L)　reached　94.31%　and　76.92%,　respectively,　in　the　simultaneous　removal　of　algae　and　algal　toxin　experiment.　Reactive　species　scavenging　experiments　demonstrated　that　O-center　dot(2)-　and　(OH)-O-center　dot　played　key　roles　in　inactivating　M.　aeruginosa　and　degrading　MC-LR.　The　excellent　recoverability　and　stability　of　ZFO/AP/CN　were　proved　by　cycling　photocatalytic　experiment　which　using　magnetic　recovery　method.　In　summary,　the　synthesized　magnetically　separable　ZFO/AP/CN　photocatalyst　has　remarkable　photocatalytic　activity　under　visible　light　and　shows　promising　potential　for　practical　application　of　alleviating　HABs.