OAO aerobic biofilm technology in the process 1 (O1), (a) 2, good oxygen (O2) composed of 3 reactors, each reactor filling designed combination of biofilm, biofilm is made up of modified block polyurethane and polypropylene exterior support material, aerobic reactor microporous aeration pipe is installed at the bottom. O1 reactor in the of wastewater in good oxygen microbial of role Xia, which of easy degradation organic was degradation for carbon dioxide and water, most of COD and the toxic material, as sulfide, and sulfur cyanate root, was removal, will conducive to reduce O2 reactor of COD load, reduced on a, reactor in the of anti-nitrification bacteria and the O2 reactor in the nitrification bacteria of impact, guarantees O2 reactor in the nitrification reaction of smooth for. A reactor can use O2 reactor reflux the mixture of NO2--N and NO3--N of denitrification, nitrate-nitrogen into nitrogen and total nitrogen, and acid hydrolysis of further degradation of refractory organic compounds as carbon source of denitrification. Nitration of O2 is mainly in the reactor, this process will be NH3-N converted to nitrate and remove part of the COD.