The invention discloses a method for producing ethanol through fermentation of a starch bearing material via a composite fungistat raw material. The method comprises the following steps: crushing the starch bearing material into powder; preparing powder slurry with a dry matter mass concentration of 30 to 33% from the crushed starch bearing material, water and a clear liquid; pretreating the powder slurry by adding acidic protease, amylase and a composite fungistat into the powder slurry, adjusting a pH value to 4.0 to 4.5 and stirring the powder slurry so as to prepare a pretreated mash, wherein the composite fungistat contains penicillin and monensin; and adding glucoamylase, yeast and nutritive salt into the pretreated mash and carrying out fermentation. A mature fermented mash prepared by using the method has high alcohol concentration and high starch liquor yield; application of the composite fungistat enables the concentrations of lactic acid and acetic acid in raw material fermentation to be reduced, mixed fungus pollution to be reduced and the alcohol concentration and the starch liquor yield of the mature fermented mash to be further improved.