Nipple invagination is a condition in which the patient’s nipple is below or not protruding from the areola plane, or in severe cases, has a crater-like appearance. Clinically, nipple invagination is usually determined by the shape of the nipple. The incidence of nipple invagination is mostly bilateral, but can also be unilateral. The incidence is about 2% and is mostly related to congenital factors, but there are also acquired ones, such as repeated breast infections, inflammation, breast cancer, breast reduction, and trauma. The clinical manifestation is that the nipple can be easily pulled out by hand and the size of the nipple is similar to that of a normal person after extrusion; Type II: moderate nipple invagination, the clinical manifestation is that the nipple can be pulled out artificially, the nipple is smaller than normal, most of them have no nipple neck and have the tendency to retract and cannot maintain its prominence; Type III: severe nipple invagination, the patient’s nipple is difficult to draw out and is completely buried under the areola. Nipple entropion is very likely to cause diseases such as inflammation of the nipple areola and inflammation of the breast, which can lead to bleeding, erosion and the formation of chronic inflammation, which can also affect breastfeeding. Prompt treatment is recommended, with appropriate repair methods depending on the type. Mild nipple invagination is treated mostly by conservative methods, such as manual traction, negative pressure suction, and appliance correction. Conservative treatment does not damage the milk ducts and is suitable for women who have not had children or for patients who require postoperative lactation to maintain normal lactation function in the future. Moderate and severe nipple invagination requires conservative treatment or surgery depending on the situation. There are more surgical treatments, including continuous traction with a nipple traction frame and loosening or cutting of the milk ducts to correct nipple invagination.