Ruling out oral cancer can be confirmed through physical examination, laboratory examination, imaging examination and pathological examination. 1. Physical examination: doctors will observe the situation in the patient’s mouth to know the location and size of the tumor and the situation of the tongue, cheek, teeth and other tissues, and also need to check the nearby lymph nodes to know whether there is any enlargement of nearby lymph nodes. 2. Laboratory examination: patients can be examined by blood routine and blood biochemistry to see if there is any infection and abnormalities in liver and kidney functions. Through the exfoliative cytology examination of tissue cells to determine the nature of the disease. 3. Imaging examination: patients can also observe the tumor foci in the patient’s oral cavity and the whole body through imaging examinations, such as X-ray, ultrasound, CT, radionuclide examination, etc., to understand the location, size and number of tumors, as well as to observe whether the patient’s tissues have any other abnormalities. 4. Pathological examination: Pathological examination is the gold standard of diagnosis, patients need to take out part of the patient’s tissues for examination under the operation of the doctor to clarify the nature of the patient’s lesions and provide evidence for diagnosis and treatment. It is recommended that patients actively cooperate with the doctor’s examination, pay attention to rest in life, maintain good habits, under the guidance of the doctor’s treatment, regular review.