A biomass gasified combustion coupling cyclone boiler solves the problems of low heat efficiency, high tar content in a gasifier, easy slagging on a high-temperature heating surface and the like in the conventional biomass boiler. The boiler comprises a jacketed boiler body and a feeding device thereof, a primary blower, a secondary blower, a circulating water pump, an ash slurry pond and a flue water mist dust remover, and adopts the following technical points: the secondary blower is connected with a jacket of the boiler body; an atomizing nozzle is formed on the inner side of the outer boiler wall; the secondary blower and a water vapor tangential spraying orifice are distributed on the circumference of the inner boiler wall; one end of a small spiral feeding machine of the feeding device is connected with the inner chamber of a gasification combustion chamber, and the other end thereof is connected with the secondary blower through a feeding air valve; and the gasification combustion chamber is communicated with a complete combustion chamber. The boiler has the advantages of reasonable structural design, stable running, energy conservation and environmental protection, enhances the heat transmission and fuel gasification effects, improves the conversion efficiency of the biomass energy and the combustion value of the gasification product of biomass fuel, enables the biomass fuel to be burned completely and fully, improves the heat efficiency of the boiler, and reduces the environmental pollution.