Photocatalysis-ultrafiltration　is　potentially　considered　to　be　one　of　the　effective　technologies　for　the　advanced　treatment　of　algae-laden　water.　However,　the　problems　of　nano-photocatalyst　loss　and　membrane　fouling　during　continuous　operation　greatly　limit　its　practical　application.　Herein,　a　novel　integrated　photocatalysis-ultrafiltration　(PC-UF)　reactor,　including　a　photocatalytic　zone,　a　separation　and　reflux　zone　of　the　nano-photocatalyst　of　Bi2O3–TiO2/PAC　(Bi-doped　TiO2　nano-composites　supported　by　powdered　activated　carbon)　and　an　ultrafiltration　zone　was　developed.　The　operating　parameters　of　the　PC-UF　reactor　were　optimized,　and　the　stability　of　PC-UF　continuous　operation　as　well　as　the　mechanism　of　the　decontamination　and　membrane　fouling　control　were　investigated.　The　results　indicated　that　the　PC-UF　reactor　was　continuously　operated　for　63　d　under　the　optimal　conditions　(Bi2O3–TiO2/PAC　dosage　of　1.0　g/L,　UV　lamp　power　of　12　W,　aeration　rate　of　200　mL/min,　hydraulic　retention　time　of　4　h,　membrane　flux　of　30　LMH,　backwashing　frequency　of　once　every　90　min　for　1　min),　and　no　obvious　loss　of　nano-photocatalyst　was　found.　The　average　removal　of　UV254,　DOC　and　turbidity　was　stable　at　61.3　%,　47.5　%　and　92.5　%.　Photocatalysis　mainly　photo-degraded　tryptophan,　fulvic　acid　and　humic　substances　fluorescent　components,　decomposed　and　mineralized　organic　matter　with　molecular　weights　of　10–5000　Da,　and　ultrafiltration　mainly　removed　microbial　metabolites　and　humic　substances.　Photocatalysis　altered　foulants　properties　by　decomposing　phenols,　amines,　and　aldehydes,　thereby　reducing　foulants-membrane　attraction　and　converting　foulant-foulant　attraction　into　repulsion,　thereby　mitigating　membrane　fouling.　This　work　provides　new　ideas　for　the　development　of　integrated　PC-UF　equipment　and　their　continuous　operation.　©　2024　Elsevier　B.V.