The invention relates to an energy-saving high-efficiency environment-friendly sewage pump, belonging to sewage treatment devices. An upper magnet and a lower magnet are respectively arranged outside a sewage pump housing, a protective cover is fixed to the sewage pump housing, an annular buoyancy chamber is fixed to the lower surface of the protective cover, and a residue filter is fixed to a water inlet on the lower end of the sewage pump housing; a drainage valve is fixed into a center hole in the sewage pump housing, a magnetic piston is arranged in the sewage pump housing, and a water-passing sealing plate seals a sewage inlet channel of a water inlet cavity and seals a sewage inlet channel of an extrusion cavity; and a fixed plug is fixed in a plug hole in the magnetism induced piston, and a sealing cap is installed on the annular sealing surface of the magnetism induced piston. The energy-saving high-efficiency environment-friendly sewage pump has the advantages of compact structure, small vibrations, high electric energy utilization ratio, strong power and high sewage pumping efficiency, and is suitable for pumping and draining sewage in a sewage treatment tank and pumping and draining sewage in a sewage precipitation tank. When the sewage pump is used for pumping and draining the sewage, sludge and mud can not enter the sewage pump. The sewage pump can convey the sewage under gravity after the power is off, thereby saving the electric energy.