NOVELTY - Producing acetone, ethanol and butanol by taking the straw as the raw material, comprises: (a) pre-treating the straw; (b) enzymatic hydrolysis of straw; (c) preparing fermentation culture medium; (d) preparation of acetone, ethanol and butanol microbial seed liquid; (e) fermenting acetone, ethanol and butanol fermentation microorganism seed liquid; and (f) solvent distillation.    USE - The method is useful for producing acetone, ethanol and butanol (claimed).    ADVANTAGE - Because the straw is used for producing the acetone, ethanol and butanol, and the Na2S is added singly to promote the fermentation, the solvent yield and the production efficiency are improved, the production cost is reduced, and the production process is simplified.    DETAILED DESCRIPTION - Producing acetone, ethanol and butanol by taking the straw as the raw material, comprises: (a) pre-treating the straw: drying, crushing and sieving the fresh straw; (b) enzymatic hydrolysis of straw obtained in the step (a) and 5% dry powder, then (60 minutes volume ratio) mixing them uniformly at 121 degrees C, using calcium hydroxide (Ca(OH)2) to adjust pH value to be 4.8, adding preprocessing enzyme, then mixing uniformly to 55 degrees C for 36-54 hours, centrifuging at a speed of 3000 rpm for 5 minutes, removing the solid substance, the supernatant is the straw enzymatic hydrolysis solution; (c) preparing fermentation culture medium using the obtained straw enzymatic hydrolysis solution, where to each liter it is added with 2 g ammonium acetate (CH3COO(NH4)), 0.6 g potassium dihydrogen phosphate (KH2PO4), 0.4 g potassium hydrogen phosphate (K2HPO4), 0.2 g magnesium sulfate (MgSO4), 1.5 g soybean powder, using Ca(OH)2 for adjusting pH is to 7.0, adding water to the anaerobic bottle to charge in the anaerobic bottle nitrogen (N2) and oxygen (O2), sterilizing at 115 degrees C for 20 minutes for further use; (d) acetone, ethanol, butanol producing microbial seed liquid fermentation: uniformly mixing the 4-6% (mass ratio) corn powder for 30 minutes, after evaporating water, N2, O2, sterilizing at 115 degrees C for 20 minutes, preparing into seed culture medium, adding 5-10% of water (by volume ratio) strain spore solution, boiling water bath heat shock for 40-60 seconds at 37 degrees C, cultivating for 18-24 hours for the microbial seed liquid; (e) acetone, ethanol, butanol fermentation in the step (c) obtained fermentation culture medium access in step (d) is 10% under the aseptic condition the volume ratio of the microbial seed liquid and the mixed vitamin solution, 37 degrees C still for 18-24 hours, separately adding sodium sulfide (Na2S), at 37 degrees C for 48-54 hours; (f) solvent distillation: using normal technique and distilling fermented liquor to obtain acetone, ethanol and butanol.