Diabetic lower extremity vascular disease is one of the common chronic complications of diabetes,which has a strong disabling effect,clinically,it is of great significance to actively and effectively control the progression of the disease and improve the quality of life of patients.In Sanxiao Lun,LIU Wansu put forward the theory of"dryness-heat and stagnation"according to the pathogenesis of consumptive thirst,and thought that the dryness-heat and stagnation in the stomach and intestines of sanjiao were too severe,the xuanfu was blocked,and the qi and liquid failed to diffuse,which caused diabetes.Vascular endothelial injury and inflammatory reaction are important factors in the development of vascular disease,the pathogenesis evolution of"dryness-heat and stagnation"conforms to the pathological characteristics of inflammatory reaction in western medicine,and the dryness-heat runs through the diabetic lower extremity vascular disease throughout.In this paper,it is believed that diabetic lower extremity vascular disease belongs to the category of"flaccidity and paralysis"in traditional Chinese medicine,and lung scorched by heat is the cause of flaccidity."Dryness-heat and stagnation"is the source of invading heat(dryness-heat),lung scorched by heat,pulse failure and vein stasis occurred,which causes diabetic lower extremity vascular disease.Treatment should be based on flaccidity,combined with the viewpoint of LIU Wansu's Sanxiao Lun,taking yangming as the top priority,regulating the triple diabetes,solving the problem of dryness-heat and stagnation,combined with the method of purging the south and supplementing the north,so that the invading heat is cleared,lung heat is diminished,and flaccidity disease cannot occur,in order to provide new ideas for the clinical prevention and treatment of diabetic lower extremity vascular disease.