For the treatment of pigmented nevus, different surgical methods are used depending on the size of the area: 1. Small pigmented nevus in the form of dots or granules can be seen on any human skin, and they are often multiple and generally do not require treatment. However, pigmented nevi located on the palm of the hand, the plantar area of the foot, the red lips or the external genitalia, or on the neck and the male lips, which are often stimulated by repeated wear and tear of the collar or shaving beard, should be treated surgically and pathological examination should be performed routinely to prevent possible cancer. 2.For pigmented nevus with slightly large area, which exceeds the limit of direct suture, or the facial pigmented nevus that can cause deformation of the neighboring organs with large tension by direct suture, it is feasible to excise and suture in stages if the site is appropriate, so as not to affect the appearance due to long-term skin color change after skin transplantation. However, if the nevus is confirmed to be a junctional nevus or mixed nevus or other pigmented nevus with malignant tendency after the first excision, then total excision and skin grafting should be performed immediately. 3. Larger pigmented nevus should be treated by excisional implantation. Full-thickness skin slice is used for the face, and local skin flap can be used when the site is appropriate. For general parts, medium-thick skin flaps can be used. It can also be combined with staged excision method, and after the maximum excision, excision implantation can be performed to reduce the area of implantation. 4.For large area of giant nevus and lesions without malignant tendency, selective excisional skin grafting is feasible to achieve the purpose of improving the appearance. 5.Cutting method: that is, the same operation as cutting medium-thick skin slice is adopted. In the area where the chipping operation is inconvenient, skin rubbing therapy is available. After chipping or erasing the wound is left to heal itself, but this method is often not very thorough, there are still pigment residues. 6, freezing, electrocautery and other treatment methods: with the same shortcomings as the chipping or rubbing therapy, neither through the treatment to obtain a pathological diagnosis, but also more difficult to complete, so its application is not very common.