With inverted A²/O process, We tried to remove the nitrogen from the actual fecal sewage and urban sewage simultaneously. Under optimal experimental conditions, nitrogen load for simultaneous removal of the critical mixture from the sewage sludge is 0.019 8 kg·kg^-1·d^-1. Hydraulic retention time is the controlling factor for mixed sewage removal. Sludge recycle ratio affects the nitrification and denitrification is weakest. In the water temperature of 28－35℃, the best condition for synchronized denitrification from the mixture of sewage nitrogen is as follow: Ammonia sludge load 0.018 kg·kg^-1·d^-1; HRT, 8 h; dissolved oxygen, 2.0 mg·L^-1; returned sludge ratio, 80%; return ratio of mixed liquor, 150%; sludge retention time, 20 d. In this condition, ammonia and nitrogen removal rate are 97.0%－99.4％ and 61.4%－68.7％, respectively. The discharged effluent could be fully treated and reached the standard.