When the nipple of the female breast does not protrude from the plane of the areola or even recesses into it, giving it a crater-like appearance, it is called nipple invagination. Nipple invagination is a relatively common deformity and is seen bilaterally. The genetic factors play an important role in congenital nipple invagination. In acquired nipple invagination, infection is one of the main factors, and it can also be caused by breast tumors, breast surgery, etc. The patient with nipple invagination should be treated as early as possible for three main purposes: 1, cosmetic: because nipple invagination affects the overall beauty of the breast, the perfect breast should have a prominent nipple. 2, breastfeeding: unmarried or married people who do not have children want to obtain a normal nipple through surgery or other methods in order to breastfeed after childbirth. 3, prevention of infection: because of the accumulation of dirt in the invaginated nipple, it is easy to attract infection. The choice of treatment for nipple invagination should be based on the purpose of the treatment, the main factor being whether or not to require breastfeeding after surgery. For those who require breastfeeding, non-surgical treatment and surgery to preserve the ducts of the breast should be the main focus; for those who do not require breastfeeding, the main goal is to make the nipple protrude and achieve cosmetic results. The principle of non-surgical treatment is to make the nipple protrude by pulling or suction, but this method is only suitable for those with flat nipples and mild invagination, while for moderate or severe nipple invagination, surgical treatment should be used. The aim of surgical treatment is to ensure good nipple shape, stability of the result, and to enlarge the nipple. The correction of nipple invagination with preservation of the milk ducts is usually done by the flap method, which involves tightening the nipple neck by a purse-string suture after reshaping the surrounding skin by removing or transferring it to achieve making the nipple protrude.