A Gas Producer Furnace refers to a reactor used to produce gas, water gas and semi-water gas. The furnace body is cylindrical, the outer shell is made of steel plate or bricks, lined with refractory bricks, and equipped with feeding equipment, blast pipes and gas pipes. According to the structure, it can be divided into mechanical generator, step generator, generator with rotating shaft and two-stage generator. According to the process, it can be divided into fixed bed or fluidized bed gas generator.