The nipple of the breast does not protrude from the areola plane but is recessed below the skin surface and is locally cratered, called nipple invagination. Not only can sunken nipples not be nursed, but they are also not easily cleaned and often become infected. In addition, sunken nipples can affect the overall aesthetics of a woman’s breasts, and patients experience varying degrees of psychological stress. The former is mainly due to mesodermal proliferation disorder, with an incidence of about 2%; the latter is secondary to breast disease. The latter is secondary to breast disease. It can be classified as mild, moderate or severe according to its degree. There are many treatment options for nipple invagination, which can be divided into non-surgical and surgical treatments, with the former mostly for mild nipple invagination and surgical treatment for moderate and severe nipple invagination. The recurrence rate of surgery is high due to the inadequate consideration of preserving the nipple duct and the supporting tissue under the nipple during surgery. In recent years, we have adopted the triangular areola flap method for the treatment of nipple invagination, which has good results because it focuses on increasing the supporting tissue under the nipple.