The invention discloses a scrap iron block washing device capable of purifying sewage. The device is composed of a material carrying frame cage, a rebar supporting frame, a steel wire rope, a micro-sized motor, a transmission pulley, a hinging rod, a washing liquid pool, a rebar bar, a bearing, a middle-sized motor, a sewage storage tank, a sewage discharging valve, a connecting cross beam, an infusion tube, a filter tank, a filter screen, a water suction pump, a solar cell panel and an energy storage box. According to the technical scheme, the device has the beneficial effects that the structure is complete, the mechanical degree is high, time and labor are saved, the use and the maintenance are convenient, water resources are saved, energy sources are clean, and the environment is protected.