Nevus, i.e. pigmented nevus, the reasons for the increasing number of pigmented nevus on the face include heredity, ultraviolet irradiation, medication, trauma and so on. Pigmented nevus is a benign neoplasm composed of nevus cells and a common benign tumor of the skin, clinically manifested as a patch or papule with uniform color and clear boundary, which is yellowish, brown or black. Pigmented nevus includes congenital and acquired, and its occurrence is related to genetic and environmental factors. The increasing number of pigmented nevi on the face may be caused by heredity, or it may be caused by ultraviolet radiation in the environment. Drugs, trauma, hormone level changes, immunosuppression and other factors may also lead to the increasing number of pigmented nevi on the face. Pigmented nevi generally do not require treatment. If the patient has cosmetic needs, they can be removed by laser, freezing, surgery, etc., and usually get better treatment results.