The invention discloses a preparation method of a feed for wild boars at a fattening period. The feed is prepared from the following components of corn, brown rice, broken rice, polished rice, unhulled rice, middling, bran, hay meal, bean cakes, cottonseed cakes, rice bran cakes, fish meal, shell powder, stone powder, table salt, complex vitamins, composite multiple minerals and a core additive, wherein the core additive is prepared from the following components of radix angelicae sinensis, aloe, magnolia soulangeana, jackinthepulpit tubers, plantain herbs, Chinese waxgourd peel, endothelium corneum gigeriae galli and semen cuscutae. The feed for the wild boars at the fattening period provided by the invention can provide basic nutrient substances for the wild boars, guarantee the growth efficiency of the wild boars, and improve the fattening efficiency of the wild boars; besides, the formula of the feed is optimized, and the core additive is added, so that the meat quality of the wild boars can also be improved; and the feed is high in safety, wide in raw material sources and low in price.