NOVELTY - Fuel alcohol is prepared by selecting dried potato waste slag after producing starch, crushing into size with granularity of 10-20 meshes, adding water, immersing for 3-4 hours, stirring uniformly and separately packing to triangular bottles in volumes of 500 mL; adding (%) cellulose enzyme (0.1-0.3), saccharizing enzyme (0.2-0.4), starch enzyme (0.1-0.3) in each bottle, and saccharizing at 50-55 degrees C for 24 hours; inoculating alcohol microzyme in malt juice and culturing for 24 hours at 30 degrees C; and distilling fermenting liquid of potato waste slag.    USE - Method of preparation of fuel alcohol (claimed).    ADVANTAGE - The method has simple technique, convenient process, ferments potato waste slag into alcohol, does not only reduces pollution to environment but also changes waste into valuable things, and saves preparing cost.    DETAILED DESCRIPTION - Preparation of fuel alcohol comprises: (A) selecting dried potato waste slag after producing starch, crushing dried potato waste slag into size with granularity of 10-20 meshes, adding water into crushed potato waste slag, immersing for 3-4 hours, stirring uniformly and separately packing to triangular bottles in volumes of 500 mL, with filling amount of each bottle of 200 g; (B) sealing openings of triangular bottles using gauzes, boiling for 30 minutes at normal pressure, cooling to room temperature, adding (%) cellulose enzyme (0.1-0.3), saccharizing enzyme (0.2-0.4), starch enzyme (0.1-0.3) in each bottle, and saccharizing at 50-55 degrees C for 24 hours; (C) inoculating alcohol microzyme in malt juice inclined-plane culture medium for activating, culturing for 24 hours at 30 degrees C, and switching to malt juice liquid culture medium, oscillating and culturing for 24 hours at 30 degrees C with 180 rpm, accessing in potato waste slag saccharizing according to inoculating amount of 10%, and fermenting for 72 hours at 30 degrees C; (F) distilling fermenting liquid of potato waste slag, distilling according to alcohol meter method of GB/T15038-2005, accurately measuring 100 mL of fermenting liquid of potato waste slag in distilling bottle using volumetric flask, washing volumetric flask for three times using 50 mL of water, and adding cleaning water in distilling bottle; (G) taking original volumetric flask for sampling as receiver, collecting distilling liquid to scale, removing volumetric flask, compensating water to scale, mixing uniformly, and measuring precision of alcohol using alcohol meter.