Pigmented nevus, also known as nevus cell nevus, is the most common benign skin tumor in human beings. Skin diseases and mucous membranes that can occur in any part of the body. It can be divided into congenital and acquired. According to the different positions of nevus cells in the skin, it can be divided into borderline nevus, mixed nevus and intradermal nevus. Pigmented nevus generally does not need treatment. Congenital melanoma may appear, and surgical resection is effective. If it occurs in the palm and sole, waist, armpit, groin and other parts that are easy to rub, surgical resection should be considered.