NOVELTY - Autotrophic denitrification of sewage, comprises e.g. inoculating sludge of a municipal sewage treatment plant in a reactor, controlling water inlet ammonia nitrogen to 80-120 mg/l, the nitrite nitrogen to 0-10 mg/l, phosphate to 5-10 mg/l and calcium oxide to 450-700 mg/l at a the temperature of 15-23 degrees C and a pH of 7.5-8-5 for hydraulic retention time of 8-15 hours using manual distribution of water under continuous aeration at an amount of 3-10 m3/(m3.h), and starting aerobic nitration stage successfully using nitrosated bacteria and denitrifying bacteria microbial system.    USE - The method is useful for autotrophic denitrification of sewage.    ADVANTAGE - The method allows simple, economical and rapid autotrophic denitrification of sewage with reduced energy consumption, high efficiency and normal-temperature.    DETAILED DESCRIPTION - Autotrophic denitrification of sewage, comprises: (1) inoculating sludge of a municipal sewage treatment plant in a reactor, where the sludge concentration is 4-5 g/l and the reactor is upflow volcanic biological ceramsite biological filter reactor; (2) controlling water inlet ammonia nitrogen to 80-120 mg/l, the nitrite nitrogen to 0-10 mg/l, phosphate to 5-10 mg/l and calcium oxide to 450-700 mg/l at a the temperature of 15-23 degrees C and a pH of 7.5-8-5 for hydraulic retention time of 8-15 hours using manual distribution of water under continuous aeration at an amount of 3-10 m3/(m3.h), and starting aerobic nitration stage successfully using nitrosated bacteria and denitrifying bacteria microbial systems successfully constructed, when the nitrate in the water has a total nitrogen ratio of greater than 50%; (3) controlling water inlet ammonia nitrogen to 80-120 mg/l, the nitrite nitrogen to 0-10 mg/l, phosphate to 5-10 mg/l and calcium oxide to 450-700 mg/l for 24 hours and controlling aeration rate to 1.8-3.5 m3 /(m3.h) for 12 hours at a temperature of 15-23 degrees C, pH of 7.5-8.5 and hydraulic retention time of 5-10 hours and then stopping aeration, where the exposure of aeration stopped ratio is 1:1, and a ratio of nitrite nitrogen and ammonia nitrogen is 1:1.3, maintaining stable operation for more than two weeks, and starting anaerobic nitrogen oxidation stage, when the delta nitrite-nitrogen/ delta ammonia-nitrogen and delta nitrate-nitrogen/ delta ammonia-nitrogen value becomes 1.2-1.4:0.2-0.3; and (4) controlling water inlet ammonia nitrogen to 80-120 mg/l, the nitrite nitrogen to 0-10 mg/l, phosphate to 5-10 mg/l and calcium oxide to 450-700 mg/l at a temperature of 15-23 degrees C and a pH of 7.5-8.5 using manual distribution of water under the aeration amount of 8.5-35 m3/(m3.h) for 0.4-5.8 hours, and starting the whole autotrophic denitrification stage in the reactor, when the ammonia nitrogen removal rate and total nitrogen removal rate of the system reach 75-90%, and delta nitrate-nitrogen/ delta ammonia-nitrogen value becomes 0.10-0.25.