The invention discloses a probiotic plant extract composite additive capable of increasing the farrowing rate of sows, and belongs to the field of feed additives. The composite additive is prepared from, by weight, 2-5 parts of lactobacillus bulgaricus, 2-6 parts of a compound plant extract, 2-5 parts of compound dietary fiber, 0.1-0.3 part of chromium yeast, 0.1-0.3 part of a cysteamine zinc complex, 0.04-0.1 part of tryptophan and 0.08-0.1 part of methionine. The composite additive is applied to sow diet, can effectively prevent constipation of the sows, increases the farrowing rate of the sows, and has a significant improvement effect on the birth weight of piglets.