The present invention relates to the field of feed, and more particularly to a biogas residue-containing feed additive for dairy cattle, which is formed by mixing the following components in the following weight unit: 20 to 50 units of biogas residue, 15 to 28 units of an astragalus residue, 10 to 12 units of an apple residue, 3 to 6 units of Caulis perillae, 4 to 8 units of Eucommia ulmoides, 3 to 8 units of pigweed, 0 to 1 unit of maca powder. The biogas residue is the resultant obtained after anaerobic fermentation of an alcohol-making mixture using cassava or sweet potatoes as raw materials for fermentation, and the resultant is dewatered by adopting mechanical extrusion, exposed in the sun and dried, and then ground by a grinder. The present invention uses scientific formulas and is highly nutritious, improves immunity of dairy cattle, reduces the occurrence of various diseases or infections during raising, and reduces the use of drugs. The effective substances of various raw materials components accumulate in tissues of dairy cattle, which also improve the milk yield.
