NOVELTY - Method for enriching cultivation of anaerobic ammonium oxidation (anammox) bacteria by membrane bioreactor, involves adding simulated sewage culture medium into membrane bioreactor water inlet box, obtaining the urban sewage plant A/O process anoxic biochemical pool sludge, performing anaerobic conservation of the sludge for 3-5 days at room temperature, and inoculating the sludge into the anaerobic jar of the membrane bioreactor, and culturing the sludge in an anaerobic jar.    USE - The method is useful for enriching cultivation of anammox bacteria by membrane bioreactor which is used in biological denitrification.    ADVANTAGE - The method improves enriching time of anammox bacteria by 80-95%.    DETAILED DESCRIPTION - Method for enriching cultivation of anaerobic ammonium oxidation (anammox) bacteria by membrane bioreactor, involves adding simulated sewage culture medium into membrane bioreactor water inlet box, obtaining the urban sewage plant A/O process anoxic biochemical pool sludge, (where temperature of the anoxic biochemical pool is 16-20 degrees C), performing anaerobic conservation of the sludge for 3-5 days at room temperature, and inoculating the sludge into the anaerobic jar of the membrane bioreactor, where concentration of the total suspending solid is 9920-9940 mg/l and volatile suspending solid is 4300-4340 mg/l, and inoculation amount is 2-4 l, (b) culturing the sludge in an anaerobic jar at 34-36 degrees C, (where pH of the sludge is regulated to 7.5-8.5, dissolved oxygen is 0.06-0.09 mg/l and pH in the anaerobic jar is 7-8, dissolved oxygen in the anaerobic jar is 0-0.01 mg/l, hydraulic retention time is 2 days, average retention time of the sludge is 1.4-1.6 minutes, total organic carbon is 0-0.01 mg/l, and organic carbon in the anaerobic jar is 18-20 mg/l, and enriching culture mode is after exhausting sludge), statically depositing and exhausting the supernatant, and culturing until the ammonia nitrogen and nitrite nitrogen in the sewage culture medium are removed. The step (a) involves dissolving (in g/l): ammonium sulfate (132-1980), sodium nitrite (69-2070), sodium nitrate (0-2550), potassium bicarbonate (1000), monopotassium phosphate (10), magnesium sulfate (60), calcium chloride (5), ferric sulfate (6.25), EDTA (6.25), zinc sulfate (430), copper sulfate (250), manganese chloride (990), nickel chloride (190), cobalt chloride (240), boric acid (14), NaCeO4.10H2O (210) and sodium molybdate (220) into water and preparing the culture medium, and boiling and removing oxygen.