Abstract: Taking Lincang coffee seed shell as raw material, through single factor experiment on seed quantity, fermentation time and nitrogen source, and on this basis, orthogonal experiment was carried out to determine the optimal technological conditions for fermentation of coffee seed shell to prepare ethanol: inoculation amount was 25%, fermentation time was 12 h, ammonium dihydrogen phosphate was 0.1%, and the actual volume fraction of ethanol was 2.80%.