The invention discloses a method for treating sewage through adoption of QTCNP technology. According to the method, aerobic denitrification composite flora and aerobic dephosphorization composite flora are added to synchronously remove COD, NH3-N, TN, and TP in an aerobic environment, and the sludge reflux ratio, the mixed liquid reflux ratio, and indexes, such as the PH value, DO value, sludge concentration, and sludge age, of an aerobic bioreactor are controlled to achieve efficient biological carbon, nitrogen and phosphorus removal. The COD removal rate can reach no less than 95%, NH3-N removal rate can reach no less than 95%, TN removal rate can reach no less than 85%, and TP removal rate can reach no less than 90%. The method is non-anoxic or anaerobic, is saved in investment, simple and stable to operate, low in treatment cost, and less in sludge production amount. The method is suitable for treating various sewage containing COD, NH3-N, TN, and TP, and can be applied to standard treatment of various sewage.