Abstract: To meet the demands of the treatment of wastewater from the soybean further processing industry,a continuous aerobic-anaerobic coupled (CAAC) process composed of moving bed biofilm reactor (MBBR) and AAC reactor was designed.The CAAC process achieved contamination removal and excess sludge reduction of anaerobic effluents from synthetic soybean deep processing wastewater through changing environmental conditions in different reactors along the flow of the stream.When the hydraulic retention time (HRT) was longer than or equal to 1.3 d, ρ(COD_Cr) was below 50 mg/L in the effluent and the removal rate of COD_Cr reached 95%.ρ(MLSS) in the effluent was controlled between 0-15 mg/L stably.During 301 days of continuous operation,a discharging sludge was completed and the observed yield of sludge was 0.1571,which was only 31.4% that of the activated sludge process.The CAAC process showed excellent excess sludge reduction.