Simmering pus and long flesh is the essence of the external treatment method of Chinese medicine surgery. The septic infection of modern medicine has its theoretical basis, and the simmering pus and long flesh of ancestral medicine also has its theoretical basis. Ancestral medicine believes that pus is the pathological product of the fight between evil toxins and qi and blood, and that suppuration is the process of identifying the pathology of the fight between good and evil. The pus is presented as yellow and thick or white and thick and tasteless, and the pus is formed rapidly; the pus is thin and slow to suppurate; the pus is depleted, the yin and blood are stagnant, and the pus and blood are fighting with evil toxins, and the result will be no pus or little pus. Simmering pus and long flesh means that the pus is in the right amount for the flesh buds to grow vigorously. According to many years of clinical practice, the argument that simmering pus grows flesh is correct. For example: pus is yellow or white thick and odorless is a sign of sufficient qi and blood to heal easily. Dry necrosis indicates the inability of Qi and blood, gangrene, such as thrombo-occlusive vasculitis, decubitus ulcers, etc., are ischemic necrosis, are difficult, this disease without pus or rarely pus. It is not until suppuration is the beginning of decay and muscle growth, indicating that there is a blood supply, the possibility of tissue resurrection, and the necrotic part is separated and shed by liquefaction and healthy tissue, and fresh flesh buds grow, so that the wound slowly heals. If the base of the necrotic tissue does not become septic, it will never separate from the healthy tissue. For example, if the wound is infected after surgery and part of the tissue is necrotic, and the patient is in poor health, western medicine often applies a lot of antibiotics to avoid further spread of inflammation, the wound rarely becomes pus, but the necrotic part of the tissue falls off slowly. If a small amount of Chinese herbal medicine “dispel rot” is sprinkled on the sore surface, and “Shengmyu Yuhong Ointment” is applied externally, it will quickly liquefy the decay and make the wound heal. The reason for this is the lack of blood supply. Chinese medicine treatment should first of all warm the meridian and disperse cold, activate blood circulation, eliminate embolism and disperse knots, nourish the blood and improve microcirculation, prompting the liquefaction of decaying tissues to fall off, and the growth of muscle and flesh, which is the unique feature of Chinese medicine. Clinical evidence shows that new flesh does not grow if there is no pus. If there is a lot of pus, then control the pus, simmering pus and long flesh and control the pus, the clinical flexibility. The simmering of pus and long flesh is the way to liquefy the decay and produce new flesh, and is the beginning of the decay and growth of muscle.