Ultrafiltration　(UF)　is　an　effective　technology　for　treating　algae-containing　water.　The　algal　intracellular　organic　matter　(IOM)　released　by　dead　algae　during　an　excessive　algae　growth　phase　causes　more　serious　membrane　fouling　than　viable　algal　cells　and　algal　extracellular　organic　matter　(EOM),　which　seriously　restricts　stable　operation　of　UF.　This　paper　studied　the　removal　of　IOM　by　a　Bi2O3-TiO2/PAC　(Bi-doped　TiO2　nano-composites　supported　by　powdered　activated　carbon)　photocatalytic　oxidation-ceramic　ultrafiltration　membrane,　the　inhibitory　effect　of　membrane　fouling　at　different　photocatalytic　oxidation　times,　and　the　fouling　mechanism.　The　results　show　that　both　the　adsorption　and　photocatalytic　oxidation　of　Bi2O3-TiO2/PAC　can　significantly　remove　proteinoids　and　humic　acid-like　fluorescent　components　present　in　IOM,　with　removals　of　UV254　and　DOC　reaching　up　to　81.8%　and　44.0%.　The　generated　superoxide　radicals　and　hydroxyl　radicals　positively　affect　the　degradation　of　organic　compounds　of　various　molecular　weights,　and　holes　mainly　degrade　acidic　low　-molecular　weight　organic　compounds.　When　the　photocatalytic　oxidation　time　was　extended　to　60　min,　the　membrane　flux　increased　by　70.7%　and　the　reversible　resistance　and　irreversible　resistance　decreased　by　83.4%　and　90.1%,　respectively.　Under　these　conditions,　the　fouling　mechanism　changed　from　complete　blockage　to　intermediate　blockage.　In　the　late　stage　of　photocatalytic　oxidation　(90-120min),　part　of　the　high　and　medium　molecular　weight　organic　components　were　oxidized　to　produce　low-molecular　weight　organic　compounds　(LMW　acidic　and　neutral　organic　compounds),　and　blockage　of　filter　cake　became　the　main　fouling　mechanism.　After　photocatalysis,　the　zeta　potential　decreases　significantly　and　the　interaction　forces　between　pollutants　and　pollutants　are　transformed　into　repulsive　forces.　Application　of　an　appropriate　photocatalytic　oxidation　time　can　alleviate　the　ultrafiltration　membrane　fouling　caused　by　algal-derived　organics.