“Interior and Exterior of Heart and Intestine” originated from traditional Chinese medicine(TCM)theory，emphasizing that “Xin(Heart)” and “Xiao Chang(Small Intestine)” have a strong correlation and work as exterior-interior viscera.This theory coincides with the concept that cardiovascular disease(CVD)is closely related to intestinal microecology confirmed by modern research.In this paper，we will clarify the“the exterior and interior relationship between heart and small intestine”by discussing the theoretical source of traditional Chinese medicine，the relationship between CVD and intestinal microecology，and the use of intestinal microecology as the target of traditional Chinese medicine treatment of CVD.It is hoped to clarify the theoretical connotation of“the exterior and interior relationship between heart and the small intestine”and to study practical significance in guiding the research of CVD and intestinal microecology，and to provide new ideas for further in-depth research and clinical diagnosis and treatment of CVD.