NOVELTY - Treating wastewater using microorganism by photocatalysis method, involves obtaining mixed solution A, subjecting the mixed solution A to centrifugal deposition, reacting centrifuged solution, inoculating microorganism to sludge in reactor, adding the carrier A obtained step (a) to the reactor, performing reaction to obtain carrier A surface, culturing microorganism in the reactor, adding culture liquid, incubating and removing sludge, and (c) maintaining hydraulic retention, adding wastewater to reactor, and controlling pH.    USE - The method is useful for treating wastewater using microorganism by photocatalysis method (claimed).    ADVANTAGE - The method improves 10-20 times degradation efficiency of organic photo-catalytic process, and easily recycles materials.    DETAILED DESCRIPTION - Method for treating wastewater using microorganism by photocatalysis method, involves (a) preparing titanium dioxide carrier by weighing polyethylene glycol and titanium dioxide, ultrasonically mixing weighed materials for 10-60 minutes to obtain mixed solution A, subjecting the mixed solution A to centrifugal deposition, reacting centrifuged solution at 70-90 degrees C for 10-60 minutes carrier, and incubating at 40-60 degrees C for 24-48 hours to obtain titanium dioxide carrier, where the carrier is loaded with titanium dioxide to obtain carrier A, and the volume ratio of the carrier and the mixed solution A is 1:(3-5), (b) inoculating microorganism to sludge in reactor, adding the carrier A obtained step (a) to the reactor, performing reaction at 20-25 degrees C, where aeration amount is 6 l/minute and hydraulic retention time is 18-30 hours, performing reaction for 5-15 days to obtain carrier A surface, where the volume ratio of the carrier A and the reactor is (0.2-0.4):1, culturing microorganism in the reactor, adding culture liquid, incubating at 20-25 degrees C, and removing sludge in the reactor to obtain carrier A surface of thickness 0.5 mm, where culture medium comprises 1-3 pts. wt. ammonium sulfate, 5-15 pts. wt. potassium dihydrogen phosphate, 5-15 pts. wt. disodium hydrogen phosphate, 5-15 pts. wt. magnesium sulfate, 1-2 pts. wt. sulfuric acid, 30-60 pts. wt. peptone and 50-100 pts. wt. glucose, and (c) maintaining hydraulic retention for 18-30 hours, adding wastewater to the reactor for 2-8 hours, providing illumination through light source, providing power of 8-25 V, collecting wastewater, and controlling pH of 5-9.