The invention relates to the technical field of animal feed, particularly to formula feed for improving the seminal fluid quality of a stock boar. The formula feed comprises: corn, soya-bean oil, wheat bran, fermented soybean meal, imported fish meal, peeled soybean meal, glucose, calcium hydrogen phosphate, stone flour, salt, sodium bicarbonate, choline chloride, compound trace elements, compound amino acids, compound vitamins, and a functional additive. The functional additive includes L-carnitine and active vitamin D3, wherein L-carnitine is a secretion of epididymis epithelium of a male animal and is beneficial for maturation and storage of sperms and activity maintenance. Through inhibition of active oxygen fragments and natural apoptosis of spermatids, the vitality and density of sperms are affected. The active vitamin D3 can efficiently inhibit antisperm antibodies and can finitely prevent hypodynamia of hind limbs of a roar. The formula feed provides all kinds of adequate nutrition necessary for healthy growth of a roar, can obviously improve the seminal fluid quality of a roar, promotes the physique of the roar to be fast recovered after hybridization, and prolongs the service life of the stock roar.