NOVELTY - The furnace has a water tank divided into a work water tank part (21) and a heat storing water tank part (18). A hot water circulating container (13), a spiral hot water circulating pipe (16) and the work water tank part are connected in series. A control switch (25) is connected with the heat storing water tank part, where a bottom pipe of the heat storing water tank part is connected with the hot water circulating container to form a loop controlled by the control switch. A steam outlet pipe (28) is inserted into a hot water circulating container made to contact with air.    USE - Energy-saving emission-reducing biomass normal/reverse combustion gasification furnace.    ADVANTAGE - The furnace is provided with ring and tail ring belts with 300 holes so as to increase temperature of the furnace. The water tank is divided into the work water tank part and the heat storing water tank part and the two parts are made to contact with air, so that the water tank is prevented from being broken by expansion and retraction. The switch circulates water in the work water tank part and increases temperature to accelerate boiling process and the water in the heat storing water tank part is automatically supplied to the boiling process so as to ensure continuous application of steam work. The hot water circulating pipe and the hot water circulating container are used for passing an exhaust pipe for discharging high-temperature gas from the work water tank part, so that heat efficiency of the furnace is improved. The furnace prevents generation of oil tar from biomass gasification process and is inexhaustible and environmental-friendly.    DESCRIPTION OF DRAWING(S) - The drawing shows a front view of an energy-saving emission-reducing biomass normal/reverse combustion gasification furnace.    Hot water circulating container (13)    Spiral hot water circulating pipe (16)    Heat storing water tank part (18)    Work water tank part (21)    Control switch (25)    Steam outlet pipe (28)