The invention relates to a low energy consumption comprehensive garbage incinerator. A material inlet and a material outlet are arranged on the body of the incinerator. One side of a supporting plate composing a hearth is articulated with the body of the incinerator and the bottom is supported by a drive mechanism. An air supply duct extending below a gap between adjacent supporting plates and above the hearth is connected with a fan. The material outlet of the hearth is downward. A grate which is arranged near the material outlet and passes the wall of the incinerator is hollow and has a sharp front end, and the upper part of the grate is cut with an air discharge hole and the back end thereof is connected with a baffle, and the air supply duct connected with the fan extends in the grate. A drive device arranged below the hearth is connected with the baffle; a movable door is arranged at the material outlet; the outside of the body of the incinerator is provided with a transmission device connected with the movable door; one side of a discharging pond connected below the material outlet is communicated with the outside of the incinerator; and the front part of a belt conveyer is in the discharging pond and extends toward the outside of the body of the incinerator. The incinerator is reasonable in structure, good in incineration effect, small in fault rate, convenient in repair and long in service life, and the scorification obtained after garbage incineration by the incinerator is small and beneficial to reuse.