A method for clean-burning micron-size biomass fuel under an adiabatic condition, the method comprising grinding raw biomass material composed of plant fiber to solid powders of micron-size biomass fuel, an average particle size of the solid powders being smaller than 400 μm; and hermetically encapsulating the micron-size biomass fuel; characterized in that the method further comprises: 1) premixing the micron-size biomass fuel with air to form a flowing dust cloud having an excess air coefficient between 0.98 and 1.25, prior to entering an industrial stove comprising an adiabatic combustion chamber; 2) ejecting the flowing dust cloud premixed in 1) to the adiabatic combustion chamber via a fuel nozzle along a tangential direction, the adiabatic combustion chamber being a sealed heat storage space and the side wall being made from an insulating material layer; setting a volumetric combustion intensity of the adiabatic combustion chamber to be between 150 kg and 350 kg of the biomass fuel per cubic meter of the adiabatic combustion chamber; surrounding the side wall using a heating body of the industrial stove, and controlling heat flowing through the side wall to be less than 10% of combustion energy of the micron-size biomass fuel; the fuel nozzle being at least one in number, and a velocity of ejection being between 1 m/s and 10 m/s; completing gasifying and burning of the flowing dust cloud at a distance between 0.5 and 2.5 time(s) the diameter of the fuel nozzle to obtain a combustion temperature between 1500°C and 1600°C; allowing extrusive flame to heat the heating body;and 3) adding steam in the adiabatic combustion chamber during combustion, and a weight ratio of the steam to the micron-size biomass fuel being between 1:30 and 1:150 to accelerate gasification and decomposition of intermediates comprising tar and carbon particles produced during the combustion prior to departing from the flame; discharging melted ash content in a form of liquid glass at a bottom part of the adiabatic combustion chamber after the melted ash content departs from the flame when the combustion is completed. 1) premixing the micron-size biomass fuel with air to form a flowing dust cloud having an excess air coefficient between 0.98 and 1.25, prior to entering an industrial stove comprising an adiabatic combustion chamber; 2) ejecting the flowing dust cloud premixed in 1) to the adiabatic combustion chamber via a fuel nozzle along a tangential direction, the adiabatic combustion chamber being a sealed heat storage space and the side wall being made from an insulating material layer; setting a volumetric combustion intensity of the adiabatic combustion chamber to be between 150 kg and 350 kg of the biomass fuel per cubic meter of the adiabatic combustion chamber; surrounding the side wall using a heating body of the industrial stove, and controlling heat flowing through the side wall to be less than 10% of combustion energy of the micron-size biomass fuel; the fuel nozzle being at least one in number, and a velocity of ejection being between 1 m/s and 10 m/s; completing gasifying and burning of the flowing dust cloud at a distance between 0.5 and 2.5 time(s) the diameter of the fuel nozzle to obtain a combustion temperature between 1500°C and 1600°C; allowing extrusive flame to heat the heating body;and 3) adding steam in the adiabatic combustion chamber during combustion, and a weight ratio of the steam to the micron-size biomass fuel being between 1:30 and 1:150 to accelerate gasification and decomposition of intermediates comprising tar and carbon particles produced during the combustion prior to departing from the flame; discharging melted ash content in a form of liquid glass at a bottom part of the adiabatic combustion chamber after the melted ash content departs from the flame when the combustion is completed.