Moles usually refer to pigmented nevi. Pigmented nevi at the corners of the mouth can usually be removed, and the effectiveness of the treatment is related to the size and depth of the pigmented nevus. Pigmented nevus is a common benign skin tumor. Clinically, the treatment of pigmented nevus is divided into surgical treatment and non-surgical treatment. 1. Non-surgical treatment (1) Laser: It utilizes selective photothermal effect to directly penetrate the skin and reach the treatment site. At present, there are common carbon dioxide laser and so on. (2) Plasma machine: It uses plasma flame to vaporize the tissue and make the lesion disappear permanently. According to the size of the lesion, the use of different diameters of the treatment needle, multi-point many times, until the naked eye can not see the black. (3) Electrocautery: It is the use of high temperature to make the lesion tissue carbonized and coagulated, so as to achieve the purpose of treatment. (4) Microwave: It is to use microwave radiation energy to make the lesion tissue carbonized and coagulated, so as to achieve the purpose of treatment. 2. Surgery: Surgical excision is the safest way to cure nevus completely. The choice of surgical method needs to be decided according to the location, depth, size of the nevus and the patient’s own conditions and other factors. The specific treatment should be based on the type of nevus and its growth area, etc. It is recommended to choose a suitable treatment plan under the guidance of doctor.