A method of brewing alcohol, comprising at least the following steps: a grinding step of materials: grinding a mixture of the materials and water to obtain a mash containing material residues; a mixture-preparing step: mixing the mash containing material residues with yeast; a fermentation step: fermenting the mash containing material residues and the yeast to obtain a fermented mash containing material residues and alcohol; and a distillation step: distilling the fermented mash containing material residues and alcohol to obtain the alcohol. The mash containing material residues is used for mixing, then the mash containing material residues and the yeast is fermented, finally the mash containing the material residues and alcohol content is distilled. Not only is the sugar in the mash converted into alcohol, but also the other contents such as fiber and residual sugar in the material residues are converted into alcohol, which improves the yield of liquor by 20% to 25% and the production cycle is shortened.