For this kind of wastewater, our company adopts the process: "pretreatment + efficient anaerobic reactor + two-stage AO(AO/ biological contact oxidation)".The process has the characteristics of low investment, good treatment effect and stable operation. The treated effluent can reach the following water quality: CODcr≤500mg/l, BOD5≤300mg/l, SS≤100mg/l, NH3-N≤35mg/l.