Chronic functional constipation is a common and refractory disease.At present，there is still no effective unified treatment plan.This paper starts from the theory of“interior and exterior relationship between the lung and large intestine”to analyze the relationship between the etiology and pathogenesis of constipation and the intestines and lungs.The research of Chinese medicine on constipation is summarized，combined with the concept of “treatment of intestinal disease by lung” and “intestinal and pulmonary diseases being treated simultaneously”.The “catharsis and regulating qi method” for the treatment of constipation is explored.Case 1 is enumerated to provide new clinical treatment ideas for chronic functional constipation.