Biomass gasifying burning boiler

The invention discloses a biomass gasifying burning boiler. The working process of the biomass gasifying burning boiler comprises a biomass gasifying stage and a fuel gas burning stage; at the gasifying stage, pyrolysis and gasification of biomass are realized by adopting a circular fluidized bed gasifying process, incompletely-reacted carbon residues are separated from generated fuel gas through a cyclone separator, and the carbon residue return to the gasifying furnace through a return feeder for gasifying once again; and at the burning stage, the separated fuel gas is dedusted through a cyclone deduster, is fed into a hearth, and is mixed with the air for burning to provide a heat source for a heated surface. According to the biomass gasifying burning boiler designed by adopting the process structure, a biomass gasifying process and the burning process of the fuel gas are separated, and fuel gas entering the hearth is high-quality fuel gas with low dust content, so that the technical problems of low burning temperature, incomplete burning, corrosion of alkali metals, dust accumulation on heated area and the like existing in the conventional biomass boiler are solved.