Signs of cancerous nevus are a great concern for patients because there are more or less nevi on human body, and nevi are prone to cancerous changes under certain circumstances. A mole should pay attention to the following conditions: 1) whether there is any change in volume, such as rapid increase; 2) whether there are symptoms such as desquamation or hair removal on the surface; 3) whether there is any change in color, such as deepening; 4) whether there are satellite foci around it, i.e. small black dots appear. In daily life, do not repeatedly stimulate moles, do not repeatedly pluck or pick moles when hair appears on the surface of moles, and do not believe in the treatment methods of prescription or drug spotting to avoid stimulating moles to become malignant. If a mole has painful symptoms or cannot be accurately judged by oneself, it is recommended to promptly consult plastic surgery to have it completely removed through surgery, and after surgery, it can be sent to pathological examination to further clarify the nature, and if there are changes in the mole, it can be further treated according to the results. If the lesion is still benign, the psychological burden can be put down.