NOVELTY - Heat is used in fast thermal cracking process of straw by drying crushed straws in trough, transporting to a material cabin, subjecting to cracking furnace for thermal cracking, separating gas from solid via dust remover of cracking system, transporting gas biomass to a tower for rectifying and washing, condensing gas exhausted from top of distillation, washing using a condenser, transporting the carbon powder to a cooler to cool the carbon powder, separating the cooled carbon powder using a dust remover, and storing the obtained carbon down in a groove.    USE - Method of using heat in fast thermal cracking process of straw.    ADVANTAGE - The method lowers production cost, and improves productivity and quality of the condensed gas and combustible gas or biomass fuel.    DETAILED DESCRIPTION - Heat is used in fast thermal cracking process of straw by:    (A) drying crushed straws in trough, transporting to a material cabin, and subjecting to cracking furnace for thermal cracking;    (B) separating gas from solid via dust remover of cracking system, transporting gas biomass to a tower for rectifying and washing, condensing gas exhausted from top of distillation, and washing using a condenser;    (C) transporting the carbon powder to a cooler to cool the carbon powder, separating the cooled carbon powder using a dust remover, and storing the obtained carbon down in a groove;    (D) cooling the heavy exhausted from the bottom of the distillation, washing, pumping obtained heavy oil to produce heavy oil of straw, and rectifying the remaining part; and    (E) separating the oil from water from the condensed oil gas to collect and produce low-boiling light oil, subjecting to heat exchanger, and sending the cold air flowing through the air pre-heater into the cracking furnace for cracking after being heated.    DESCRIPTION OF DRAWING(S) - The drawing is a flow chart of a method of using heat in fast thermal cracking process of straw. Drawing includes non-English language text.