The invention discloses an antiviral livestock and poultry health care feed additive. The antiviral livestock and poultry health care feed additive comprises the following raw materials in parts by weight: 20-40 parts of weeping forsythia capsule, 40-60 parts of glabrous greenbrier rhizome, 10-30 parts of white hyacinth bean, 10-30 parts of common yam rhizome, 10-20 parts of wrinkled gianthyssop herb leaf, 10-20 parts of chicken's gizzard-membrane, 10-20 parts of largehead atractylodes rhizome, 10-20 parts of costustoot, 10-30 parts of gordon euryale seed, 10-20 parts of tangerine peel, 10-30 parts of honeysuckle flower and 10-20 parts of barbary wolfberry fruit. The weeping forsythia capsule and honeysuckle flower in the antiviral livestock and poultry health care feed additive disclosed by the invention can efficiently decompose deposited toxins in livestock and poultry, strengthen the detoxification capability of the liver, improve the antiviral capability of the livestock and poultry and prevent various infectious diseases; the glabrous greenbrier rhizome, the white hyacinth bean, the common yam rhizome, the wrinkled gianthyssop herb leaf, the chicken's gizzard-membrane, the largehead atractylodes rhizome, the barbary wolfberry fruit, the costustoot and the gordon euryale seed are matched for use so as to realize the effects of realizing broad-spectrum antibacterial property, clearing heat and toxin, stopping diarrhea, stopping vomiting, invigorating the stomach, promoting digestion and increasing appetite. The antiviral livestock and poultry health care feed additive disclosed by the invention takes natural traditional Chinese medicines as raw materials, thus having the advantages of high safety, no side effects, low cost and simplicity in manufacturing.