Pretreatment method of corn straw for preparing ethanol

The invention relates to a pretreatment method of corn straw for preparing ethanol, which comprises the following steps: (1) chopping a corn straw raw material, soaking the chopped corn straw raw material, and dehydrating the soaked corn straw raw material by using a screw extruder; (2) cooking the corn straw raw material subjected to dehydration treatment in the step (1) by an ammonium sulfite method to obtain slurry; (3) adjusting the slurry concentration of the slurry cooked in the step (2) to be 10-15%, and performing slurry grinding treatment to obtain pretreated slurry; and (4) carrying out enzymolysis on the pretreated slurry obtained in the step (3) to obtain an enzymolysis product, and fermenting the enzymolysis product to prepare the ethanol. According to the corn straw pretreatment method provided by the invention, the consumption of an enzyme preparation in the enzymolysis stage is reduced, the cost is reduced, and the efficiency of producing ethanol from the corn straw is effectively improved. 本发