I. Clinical data The patient, male, 17 years old, was found to have local black skin lesions on the glans and foreskin for more than 1 month. The lesion at the glans was nearly round, about 1cm×1.5cm in size, and the lesion at the inner foreskin was about 0.6cm×0.8cm in size. the lesion was flush with the skin surface, no hair growth, no ulceration or exudation, and no tenderness. He was admitted to the hospital as glans intradermal nevus. After completing the preoperative examination, the external genital pigmented nevus was excised under local anesthesia and repaired by combined circumcision with dorsal penile venous nutrient vascular flap. The specific surgical method: the excision line was designed 1 mm outside the glans head nevus, the circumcision line was designed 1 mm outside the nevus along the foreskin, and the island flap of the inner foreskin plate was marked with the superficial venous trunk of the tethered area as the tip. After local infiltration anesthesia, the glans nevus was excised, proper hemostasis was achieved, the inner foreskin plate island flap was separated and concealed and transferred over the wound surface, and the wound edge was placed with 5-0 fast Viejo sutures in counterpoint and drainage strips were placed. Conventional circumcision was performed along with removal of the inner plate nevus, preserving the corresponding size of inner plate skin below the glans nevus, leaving a sterile catheter in place, and moderate pressure dressing with petroleum jelly gauze and sterile dressing in the operative area. Postoperative pathological examination showed that the (glans) intradermal nevus, the base and each cut edge had been excised. At the follow-up 12 days after surgery, the appearance of the penis was satisfactory. The latter two have the potential tendency to turn into malignant melanoma. Split nevus (kiss-like nevus) is a kind of dark pigmented nevus that occurs during the embryonic period (from the 9th week to the 7th month), but split nevus is not common, and there are more reports of split nevus on eyelid in China, but split nevus on penis has not been reported, and the genetic mechanism is not clear. All nevi are found on the human surface in varying numbers and generally do not require treatment. However, for lesions with larger area, especially those occurring in exposed parts such as face, eyelids, ears and hands, or those often receiving wear and tear, such as the back of neck, fingers, palms and plantar areas, or some special parts, such as penile head and red lips, especially those pathologically diagnosed as junctional nevus or mixed nevus, there is a certain tendency of malignant transformation, and once malignant transformation occurs, the mortality rate is high, so early treatment is advocated. Treatment of pigmented nevus: It is mainly determined by the size, location and nature of the nevus, including freezing, electrocautery, grinding, laser, moxibustion, surgery, etc. Freezing and laser. If the depth of treatment is not well grasped, the mole may not be removed completely or scar left behind, therefore, surgical treatment is mostly used at present. The depth of surgical excision should reach the subcutaneous tissue, and the excision range should exceed the edge of the lesion by 2-3mm in order to achieve complete eradication. The surgical treatment of large nevus of the penis has been rarely reported in China. In this case, due to the relatively large area of the nevus nigricans and its location at the glans, it could not be sutured after excision due to the uniqueness of the lesion location. We adopted the surgical method of circumcision of the nevus of pigmentation at the foreskin and reserved the local inner plate to form an island-shaped flap to repair the wound.