Simultaneous nitrogen and phosphorus removal performance of a kind of biomembrane process integrated with partial circulatory aeration and two-stage treated water returning alternately was studied by utilizing the technology to treat typical decentralized wastewater from Modern Agricultural Science and Technology Innovation Base in Tianjin. The system with a total effective volume of 234m3 was composed of collecting tank, hydrolysis acidification balance tank, partial aerobic tank, secondary sedimentation tank and circulation tank. Sewage pumps in collecting tank were controlled by PLC automatic control system. Sludge pumps in secondary sedimentation tank worked 10min every 2h controlled by PLC automatic control system. Circulating water pumps in circulation tank controlled by PLC automatic control system could maintain necessary water flowing when inflowing and sludge returning were simultaneously stopped. The nominal air delivery of clover roots blowers in equipment room was 2.0m3/h. Hydrolysis acidification balance tank and partial aerobic tank were both filled with combined biocarrier at a filling height of 2m and the filling percentage and hydraulic load of the two tanks were 60%, 1.25m3/(m3·d) and 70%, 20m3/(m3·d), respectively. The operation of the whole system was controlled by PLC. Pumps for inflow worked intermittently and total time of it’s working was 6h every day. Aeration was continuous and partial. Since June, 2013, the test running was completed, the system was always operating formally in the way of intermittent inflow, partial aeration and alternate wastewate return. The raw decentralized wastewater was discharged from office buiding, research activities building, expert floor, restaurant, guest house and industry incubator and except for those from restaurants and toilets, which were firstly discharged into oil separation tank and septic tank for pretreating, the most was discharged directly into the system to treat. The designed treating capacity of this system was 150m3/d and the maximum influent quantity, minimum influent quantity and average influent quantity in reality was 140m3/d, 80m3/d and 100m3/d, respectively. The return ratio was controlled at 2∶1 by PLC. Through long tem operation of two years, the results showed that the average removal percentages for BOD5, NH3-N, TN and TP were 71.6%, 64.4%, 45.5% and 72.0%, respectively, and the average effluent concentrations of BOD5, NH3-N, TN and TP were 15.3mg/L, 9.2mg/L, 17.2mg/L and 0.8mg/L,respectively. It was indicated that the quality of treated effluent was up to “Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant” level 1B and treated water can be used as irrigation water. Nitrogen and phosphorus removal function was also well established when treating decentralized wastewater with high fluctuation and high loading. And it was further observed that removal percentages for BOD5, NH3-N and TP were increased with the increase of BOD5/TN and removal percentage for TN was decreased with the increase of BOD5/TN and BOD5/TP, while TN/TP was not one of main contributors to affecting removal percentage of BOD5, NH3-N, TN and TP.