The traditional Chinese medicine feed additive fermented by microorganism is a perfect combination of traditional Chinese medicine feed additive and probiotic feed additives.It is not only can improve animal immunity and promote animal growth but also an ideal substitute for antibiotic feed additives.This article expounds the mechanism of microbial fermentation medicine,the change of traditional Chinese medicine property after fermentation,probiotic feed additives and the traditional Chinese medicine feed additive fermented by microorganism.