Moles on the genitals may be related to congenital developmental defects, genetic mutations, ultraviolet radiation, trauma, hormonal imbalance and other causes. Mole is a general term for a group of skin diseases, different types of moles have different causes, and the causes of most moles are still unclear. The occurrence of congenital nevus is mainly related to gene mutation during embryonic development, resulting in developmental defects. The main cause of acquired nevi is ultraviolet radiation, followed by trauma, hormonal secretion changes, drugs, immunosuppression abnormalities and other causes. The onset site of nevus is more complicated, some preferably occur in the head and face, and some preferably occur in the limbs, trunk and other places, so the patient’s genitals will have nevus. Usually, most moles do not require treatment and have no effect on health. If there is a tendency for the mole to become malignant, the patient needs to go to the hospital in time, complete the examination and cooperate with the doctor for active treatment.