The invention discloses a method for conveniently and quickly purifying dihydromyricetin from ampelopsis grossedentata leaves. The method comprises the following steps: a, crushing ampelopsis grossedentata leaves, extracting the crushed ampelopsis grossedentata leaves by using alcohol/water with the volume fraction of 70-90%, and separating in a centrifuging or filtering manner to obtain an alcohol extracting solution, wherein the used alcohol is ethanol, methanol or isopropanol; b, adding water into the alcohol extracting solution, removing the alcohol solvent in the alcohol extracting solution through reduced pressure distillation under the water bath condition of 40-50 DEG C, gradually separating out solids from the remaining water-based solvent along with the gradual distillation removal of alcohol from the solvent, standing for cooling to room temperature, and then centrifuging or filtering to remove water to obtain a primarily extracted solid; and c, washing the primarily extracted solid with water, then carrying out suspension washing with an alcohol-containing ethyl acetate, alcohol-containing dichloromethane or alcohol-containing chloroform mixed solution, filtering to remove the washing solution, and drying to obtain dihydromyricetin, wherein the used alcohol is ethanol, methanol or isopropanol. The method has the advantages of simple operation, high extraction yieldand the like.