Abstract：Community-acquired pneumonia(CAP) is a common respiratory disease and a serious threat to physical and mental health. In recent years，with the in-depth study of the pathogenesis of CAP，more and more evidence has shown that intestinal flora is closely related to the occurrence of CAP. The understanding of the physiology and pathology of the lung and large intestine in Chinese medicine theory of “the interior- exterior relationship between the lung and large intestine” provides a new idea for the treatment of CAP from the perspective of intestinal flora. From the theoretical understanding of “the interior- exterior relationship between the lung and large intestine”， the composition and function of intestinal flora，the richness of intestinal flora，the number of probiotics and the maintenance of intestinal barrier function， this paper discuss the role of CAP and intestinal flora， and summarize the research contents of single Chinese medicine， Chinese medicine compounds and Chinese medicine external treatment regulating intestinal flora in the treatment of CAP，so as to provide new ideas for the treatment of CAP with Chinese medicine.