To summarize the clinical experience and characteristics of Professor Wang Wanchun's treatment of chronic refractory wounds based on the theory of three causes. The etiology and pathogenesis of the disease were summarized by internal causes, external causes, not internal and external causes, and it was believed that the pathogenesis of the disease was mainly caused by wind, cold, wet and heat. Seven emotions, to the heart, and the spleen and kidney for internal causes; Combined with the modern point of view to extend the diet work and rest, insects and animals injuries, cancer gas secondary, diabetes and other complications are not internal and external causes. Therefore, the treatment is based on the principle of three reasons to adjust the conditions, and the prescription follows the time to improve the health of muscle, and put forward the heart to help the health of muscle as the basis, according to local conditions, support the spleen to produce muscle; In order to provide reference for the clinical diagnosis and treatment of chronic wounds, the clinical thinking of invigorating kidney and promoting muscle is different to different persons.