Practical　applications　of　photocatalysis　in　algae　removal　often　involve　the　use　of　photoreactors,　which　can　be　of　many　different　configurations.　In　this　study,　a　fluidized　bed　photoreactor　(FBPR)　with　an　external　magnetic　field　was　designed　and　constructed　to　achieve　algae　inactivation　continuously　and　stably.　Magnetic　photocatalyst　ZnFe2O4/Ag3PO4/g-C3N4　attached　to　Fe3O4　aggregate,　was　dispersed　and　fixed　at　the　bottom　of　the　reactor　to　form　a　flower-like　structure,　which　can　not　only　increase　the　effective　irradiation　area　of　the　photocatalyst,　but　also　enhances　mass　transfer　by　inducing　flow　disturbance.　Under　the　optimal　operating　conditions,　i.e.,　0.04　m/s　flow　rate,　200　mT　magnetic　field　strength,　and　0.025　g　photocatalyst　loading,　the　photoreactor　can　effectively　remove　algae　cells　within　6　h.　During　the　continuous　operation　experiment,　the　quality　of　the　magnetic　photocatalyst　and　aggregate　did　not　decrease　significantly,　and　there　was　still　a　90%　removal　efficiency　after　18　h　of　continuous　operation.　Furthermore,　in　the　experiment　where　humic　acid　was　added　to　simulate　actual　water　environment,　certain　advantages　can　still　be　observed　with　the　FBPR.　As　a　continuous　reactor　using　a　magnetic　photocatalyst,　the　FBPR　has　the　characteristics　of　high　availability,　low　cost,　and　low　energy　consumption.