The invention provides a sewage treatment method and relates to the technical field of environmental protection. The method comprises operating steps as follows: sludge concentration devices are additionally mounted at side parts of a regulating tank, a coagulation tank, a primary sedimentation tank, an electrolytic tank, a contact oxidation tank and a secondary sedimentation tank, sludge inlets of the sludge concentration devices are connected with sludge discharge pipes at bottoms of the tanks, and liquid discharge pipes in the sludge concentration devices are connected to water inlet pipesabove the corresponding tanks; raw sewage is fed into the regulating tank after passing through a coarse grating and a fine grating, precipitated flocculates are sent into the corresponding sludge concentration device through the corresponding sludge discharge pipe for sludge concentration, and concentrated liquor is transported into the coagulation tank again. Sludge dewatering treatment can be performed on the sludge produced at each stage of sewage treatment, the dewatered sludge is transported to the corresponding treatment tanks for retreatment again, so that treatment burden of the sludge is reduced, the treatment burden of the primary sedimentation tank for backflow sewage is reduced, and practicability is higher.