NOVELTY - Extracting fuel ethanol by crushing and fermenting whole sweet sorghum with double enzyme comprises crushing straw, grinding, mixing slurry, fermenting, roughly distilling, finely distilling, and purifying by molecular sieve.    USE - The method is useful for extracting fuel ethanol (claimed).    ADVANTAGE - The method can be controlled easily.    DETAILED DESCRIPTION - Extracting fuel ethanol by crushing and fermenting whole sweet sorghum with double enzyme comprises crushing straw, grinding, mixing slurry, fermenting, roughly distilling, finely distilling, and purifying by molecular sieve. The method specifically comprises: (a) crushing sweet sorghum or sweet corn raw material into sections of less than 15 mm; (b) grinding by milling the crushed raw material sections into short and thin fiber slurry and sieving the slurry by a sieve of 5-15 meshes by shaking, and transferring the filtered solution into a grinding pot and the solid further grinded; (c) mixing the slurry by adding water into the filtered solution and adjusting the concentration of the slurry until the dry mass concentration is 20-25%, the acidic pH is 4-5, and the temperature is 28-30 degrees C; (d) placing the slurry into a fermenting tank; yeast, cellulase, and carbamide nutritive salt are added in batches to ferment, where the added amounts are: the yeast is 0.03-0.05% of the total mass of the liquid, the cellulase is 12-13% of the total mass of the liquid, and the carbamide nutritive salt is 0.01-0.02% of the total mass of the liquid; (e) performing fermentation; (f) performing distillation: (i) rough distilling system: the operation control indexes are as follows: the temperature of the tower bottom is 85-87.5 degrees C and the temperature of the tower top is 62.5-70 degrees C; the pressure of the tower bottom is negative 45-50 kPa and the pressure of the tower top is negative 65-70 kPa; the diluted ethanol and the waste swort liquid containing solid are separated; and (ii) the diluted ethanol is led into finely distillation: the operation control indexes are as follows: the temperature of the tower bottom is 119-123 degrees C and the temperature of the tower top is 93-98 degrees C; the pressure of the tower top is negative 0.07-0.10 Mpa and the pressure of the tower bottom is negative 0.10-0.12 MPa; the feeding temperature is 110-116 degrees C and the side-drawing temperature is 93-94 degrees C; where ethanol with a concentration of 95% is prepared; and (g) the ethanol is led into the molecular sieve: the operation control indexes are as follows: the operation pressure is 2.20-0.35 Mpa and the outlet temperature is 100-125 degrees C; the operation pressure in the absorption process of an absorption tower is 0.20-0.35 Mpa and the gas inlet temperature is 120-145 degrees C; the operation pressure in the process of desorption is negative 0.02-0.05 Mpa and the outlet temperature is 180-230 degrees C; and extracting the finished fuel ethanol product having a concentration of more than 99.2%.