NOVELTY - A domestic sewage is treated by introducing domestic sewage into sedimentation tank and then flowing top clarifying solution flows into anaerobic reactor; anaerobic treating sewage, where anaerobic organisms grow on flexible solid stuffing in the form of biological membrane; anaerobic digesting of sewage sludge; receiving sewage sludge at bottom of sedimentation tank by water inlet pipe and then processing anaerobic digestion to sewage sludge; and flowing top clarifying solution after anaerobic digestion into first grade anaerobic reactor through water outlet pipe.    USE - Method for treating domestic sewage (claimed).    ADVANTAGE - The method ensures system stability, reaches drainage standard and reinforces safety performance.    DETAILED DESCRIPTION - Domestic sewage is treated by introducing domestic sewage into sedimentation tank and then flowing top clarifying solution flows into anaerobic reactor; anaerobic treating sewage, where anaerobic organisms grow on flexible solid stuffing in the form of biological membrane; anaerobic digestion of sewage sludge; receiving sewage sludge at bottom of sedimentation tank by water inlet pipe and then processing anaerobic digestion to sewage sludge; and flowing top clarifying solution after anaerobic digestion into first grade anaerobic reactor through water outlet pipe. The top end of sewage sludge digestion reactor is 0.8-1 m below ground. The upper end of sewage sludge digestion reactor is connected with biogas outlet pipe. The upper part is connected with water outlet pipe and its lower part is connected with water inlet pipe. The flexible solid filling of polypropylene is provided at center of sewage sludge digestion reactor. The anaerobic organisms grow on flexible solid stuffing in the form of biological membrane. The filling processes ultrasonic treatment is carried out at vibration frequency of 30-40 KHz and 50-100 W for 5-8 hours.    DESCRIPTION OF DRAWING(S) - The drawing is a schematic diagram illustrating a method for treating domestic sewage. (Drawing includes non-English language text).