The invention discloses a
biomass semi-gasification furnace comprising a burner, a vaporizing chamber, a filling mouth, a
flame bridge, an ash receiving and ventilating chamber, a secondary air
inlet channel, a panel fire surrounding cover and a
flue, a circumference space, an insulating layer, a fireproof ring, an
air blower mouth and the like. The invention prefabricates accessories, such as the burner, the vaporizing chamber, the panel fire surrounding cover, the
flue, the filling mouth, the secondary air
inlet channel, the
flame bridge and the like which have different specifications and are matched as well as prefabricates square or round
metal furnace periphery or cooking bench periphery built by bricks and mud; all accessories are connected, and the insulating layer is built by
fire clay. The invention eliminates a
dead space formed on the joint of the burner and the vaporizing chamber and increases the
flammable gas rising flowability; secondary air inlet is high-temperature wind so as to greatly improve
combustion-supporting efficiency; third air inlet supplements the insufficiency of secondary supply air rate when fuel with a higher gas
production rate is burnt, so that
biomass raw material can be more evenly and completely burnt. The accessory of the product of the invention can be produced in a standardized and industrialized mode, thus lowering cost and bringing convenience for popularizing products.