The invention discloses a Chinese herbal medicine additive for improving the fertility of sow. The Chinese herbal medicine additive comprises, by weight, 2-10 parts of herba leonuri, 2-10 parts of eucommia ulmoides, 2-10 parts of herba epimedii and 1-5 parts of Himalayan teasel roots. The invention further discloses a method for preparing the Chinese herbal medicine additive. The Chinese herbal medicine additive and the method have the advantages that the Chinese herbal medicine additive is scientific in combination and has obvious effects of preventing diseases and protecting health of the sow, improving the production performance of animals, improving the quality of animal products and the quality of fodder and the like; the effects of preventing the diseases and protecting the health of the sow are mainly represented in the aspects of enhancing the immunity of the sow, inhibiting bacteria, expelling parasites, regulating functions of the sow and the like; the effect of improving the production performance of the sow is mainly represented in the aspects of promoting the growth of the sow, promoting the development of the reproductive organs of the sow, increasing a pregnancy rate and a farrowing rate and reducing a piglet mortality rate; the effect of improving the quality of fodder is mainly represented in that the Chinese herbal medicine additive has effects of supplementing nutrition, enhancing aroma and deodorizing, preventing mildew and rotting and the like, accordingly, the nutrition of the fodder is improved, the appetite of the sow is promoted, the shelf life of the fodder is prolonged, and the like.