The invention relates to a compound feed additive for pigs, as well as a preparation method and application of the compound feed additive. The feed additive comprises the following components in partsby weight: 19-33 parts of a plant extract, 5-7 parts of yeast beta-glucan, 1.52-4.06 parts of an organic trace element chelating substance and 55.94-74.48 parts of a carrier substrate. The preparation method comprises the following steps of during preparation, firstly, preparing raw materials, dividing the carrier substrate into a carrier substrate A and a carrier substrate B, screening the plantextract, then adding the screened plant extract to a mixture of the carrier substrate A with the organic trace element chelating substance, performing uniform stirring, then adding a mixture of the yeast beta-glucan and the carrier substrate B, and performing uniform stirring. The feed additive is added to a basic ration of the pigs, and the addition proportion of the feed additive to the basic ration in percentage by weight is 0.5-1.5%. Compared with the prior art, the compound feed additive disclosed by the invention has the advantages that the immunity of animals can be notably improved, the attack rate can be reduced, antibiotics and chemical synthesis medicines can be replaced, the safety of meat products is improved, the mouth feel of meat quality is improved, besides, the growth and the development of the animals can be notably promoted, and the utilization efficiency of the feed can be improved.