The invention provides a feed additive capable of resisting swine viral diseases. The feed additive comprises the following components in parts by weight: 5-10 parts of yolk antibody lyophilized powder for resisting the swine viral diseases, 1-3 parts of the whole plant of epimedium, 2-5 parts of betaine and 2-5 parts of squalene. The feed additive is composite yolk antibody powder, and has a better prevention and curative effect compared with single yolk antibody powder; according to the feed additive, the effect in preventing the swine viral diseases is obviously improved, the effect of the feed additive is significantly better than that of separately added components or separate combination of single component, and each component plays an essential role on realization of the effect.