Parotid adenoma is a benign tumor that is not serious, but if it is malignant, it can be serious enough to require surgical removal. Parotid adenoma is a common disease in oral and maxillofacial surgery, which occurs in the middle-aged population, with benign tumors prevalent, accounting for more than 80% of tumors in the parotid gland. However, once benign tumors become malignant, it is very serious. About 5% of benign tumors can become malignant, and epidermoid carcinoma of breast accounts for the first place of malignant tumors, and the longer the course of benign tumors, the higher the possibility of malignant transformation. Mechanical stimulation or temperature changes including sunlight exposure can accelerate the malignant transformation. Clinically, sudden growth of tumor and rapid growth, reduction of tumor mobility, sudden decrease in range of motion or immobility, or painful symptoms, serious invasion of facial nerve and facial paralysis are all signs of malignant transformation. It must be removed by surgery as soon as possible. Therefore, benign parotid adenoma without symptoms is not serious, but if not removed in time, the possibility of malignancy increases and can be serious.