The cause of non-lactating mastitis is unknown, and some people believe it is an autoimmune disease, and the lesions are usually very large when the patient is seen, as shown in the illustration, there is a “rotten pear”. Therefore, the timing of surgery is very important, too early to grasp the timing will be too large tissue removal and lead to breast deformation; too late will be due to the lesion again recurrence and increase the size of the excision repair difficulties.