Abstract: Fermented traditional Chinese medicine is a kind of traditional Chinese medicine with new components and functions formed by in vitro microbial fermentation process, which endows traditional Chinese medicine with unique pharmacological and pharmacodynamic characteristics and has broad application prospects. Complex chronic diseases are closely related to intestinal barrier and intestinal flora, and intestinal microorganisms are widely involved in the metabolic processes and pharmacological effects of traditional Chinese medicine, and it has become a new trend to investigate how fermented traditional Chinese medicine regulate the intestinal microenvironment. This paper reviewed the mechanism of fermented traditional Chinese medicine in improving intestinal barrier function including mechanical barrier, immune barrier, chemical barrier and biological barrier and regulating intestinal flora, and compared the differences between fermented traditional Chinese medicine and traditional Chinese medicine to provide reference for further in-depth investigation of the relationship between fermented traditional Chinese medicine and intestinal tract, in order to better reveal the core connotation of fermented traditional Chinese medicine in treating diseases and promote the modernization of Chinese medicine.