The invention relates to a system and a method for treating household garbage. The system comprises a pre-treatment system, a revolving bed pyrolyzing furnace, a deacidifying-waste heat recovery system and an inert gas preheating system which are connected. The pre-treatment system comprises a garbage raw material inlet and a garbage raw material outlet; the revolving bed pyrolyzing furnace comprises a material inlet, a pyrolytic gas outlet, a pyrolytic carbon outlet and a fuel inlet; the deacidifying-waste heat recovery system comprises a pyrolytic gas pipeline; the inert gas preheating system comprises an inert gas pipeline; the deacidifying-waste heat recovery system and the inert gas preheating system also comprise a first reversing valve, a first deacidifying-heat storage device, a second deacidifying-heat storage device and a second reversing valve, wherein the first deacidifying-heat storage device and the second deacidifying-heat storage device are arranged in parallel. According to the method for treating the household garbage by utilizing the system provided by the invention, acid gas in the pyrolytic gas is removed by a deacidifying-heat storage complex, and meanwhile, the inert gas can also be preheated by reversing of the reserving valves so that the waste heat of the pyrolytic gas is recovered and utilized. According to the system and the method, energy can be saved, emission can be reduced, and production cost can also be reduced.