Provided is a biomass micron fuel high-temperature cleaning and combustion method based on adiabatic combustion conditions, comprising: (a) in entirely sealed form, a biomass micron fuel is filled, handled, and transported, and delivered via a pipe to an industrial furnace; (b) the biomass micron fuel is premixed with air to form a dust cloud in fluid form; (c) the premixed fluid dust cloud is sprayed, via a fuel nozzle, into the adiabatic combustion chamber (1) arranged in the furnace; the energy of the biomass fuel having a relatively low energy density is accumulated in the closed heat storage space opposite the combustion chamber, and the closed storage space performs ultra-high-temperature combustion; (d) during the process of combustion, steam is added to the adiabatic combustion chamber (1).