The invention relates to the field of sewage treatment, and in particular relates to an anaerobic baffled reactor. The anaerobic baffled reactor sequentially comprises a high-level water tank, an ABR (anaerobic baffled reaction) tank and a constant-temperature system, and is characterized in that 6 compartments are connected in series to form the ABR tank, the fifth compartment is an anaerobic reaction tank, the sixth compartment is an aerobic reaction tank, and a plurality of microporous aeration holes are formed in the sixth compartment aerobic reaction tank. According to the anaerobic baffled reactor, the anaerobic section and the aerobic section are added, so that the COD (chemical oxygen demand) removal rate is increased to 95.58 from 73.98 percent, the effluent concentration of ammonia nitrogen can be effectively reduced, and the effluent can completely achieve the wastewater emission standard of beer.