The sudden appearance of small black moles on the face may be related to ultraviolet radiation or endocrine disorders. In daily life, it is necessary to strengthen sun protection measures, eat regularly, exercise appropriately and develop good habits of life and rest. Besides, the treatment should be decided according to the size, shape and accompanying symptoms of the mole. If the mole has regular edges, uniform color, no rapid or continuous enlargement, and no pain or itching, the risk of malignant transformation is low, and if it has no obvious effect on the appearance, it can usually be left untreated. Treatment. When small nevus on face has the risk of malignant transformation, it will generally show irregular edge, uneven color, significant and rapid enlargement, obvious deepening of color, repeated infection, breakage, crusting or frequent pain of the nevus, and frequent bleeding. Patients are advised to go to the hospital for dermoscopy or skin pathology biopsy, etc., to determine the nature of small nevi, and if necessary, surgical excision treatment. In addition, if multiple small star-shaped nevi appear around a small nevus or several nevi fuse with each other, it is recommended to expand the area of surgical excision or undergo laser treatment as early as possible. In clinical practice, we can also choose freezing method and electrocautery method to treat small nevi, but we should pay attention to never scratch the nevus by ourselves and apply corrosive agents indiscriminately so as not to stimulate the nevus and inflame it, creating conditions for malignant transformation.