The invention discloses a feed additive promoting growth of a crossbred of a wild boar and a hog. The feed additive is prepared by the following raw materials in parts by weight: 5-10 parts of bidens biternata, 5-11 parts of japanese cayratia herb, 6-10 parts of panax notoginseng, 6-12 parts of asarum, 4-8 parts of cinnamon, 4-10 parts of jujube, and 4-9 parts of herba eupatorii. The feed additive rationally selects Chinese herbal medicine geo-authentic crude drugs according to physiological and hereditary characteristics of the crossbred of the wild boar and the hog; the prescription has efficacy of helping digestion, removing retention, strengthening the spleen, promoting appetite, regulating the flow of qi, activating blood circulation, and clearing away heat and toxic material, can remarkably improve average daily gain of the crossbred, feeding stuff conversion rate, and carcass character indexes, and remarkably reduce material meat ratio, and has the characteristics that the feed additive is natural in source, various in function, residual free, and free from toxic and side effect; the preparation method is simple, feasible, safe and reliable.