The invention discloses a combustion-supporting type household garbage incineration device. The combustion-supporting type household garbage incineration device is characterized by comprising a furnace body, a hearth, fire bars, a feeding port, a smoke outlet, a slag discharging port and a methane tank, the furnace body is a trapezoid with the cubic lower middle portion and the pyramid upper middle portion, the fire bars are vertically arranged in a step shape, the fire bars on the lower portion are arranged in parallel, a cold air preheating pipe is arranged on the upper portion of the hearth, an outlet header pipe of the preheating pipe is connected with an air pump outside the furnace body, hot air is conveyed back into the furnace body through the air pump, and the lower portion of the furnace body is provided with a methane inlet communicated with a methane storage tank of the methane tank. According to the combustion-supporting type household garbage incineration device, hot air and methane are used for supporting combustion, the temperature of the furnace body is high, combustion is thorough, the dioxin is split, the whole processing process is friendly to the environment, and secondary pollution does not exist.