1. Medical history should pay attention to the time of tumor discovery, initial site and growth rate, the presence of symptoms such as tracheal and esophageal pressure, cough and hoarseness, the presence of hyperthyroidism, the presence of head and neck radiation treatment officials and family history. Pay attention to the tumor located in one lobe or the whole thyroid gland, and accurately record its size, shape, mobility, hardness and degree of up and down movement when swallowing. Check the relationship between the tumor and adjacent tissues and organs (such as clavicle, carotid artery, esophagus, trachea, larynx, etc.) in detail. Check whether there is enlargement of cervical lymph nodes, and note in detail their number, location, nature and mobility. 3. If necessary, cervical and chest X-ray should be performed to observe the position, direction and degree of displacement of larynx and trachea, and to determine whether the tumor has extended to the posterior sternum and lung metastasis. 4.If it is not easy to confirm the diagnosis, the following tests can be done: ultrasound, thyroid nuclear scan; measurement of serum anti-thyroglobulin antibody, anti-thyroid microsomal antibody, immunoglobulin, T3, T4, thyroglobulin (Tg), TSH, etc. 5.Check blood sedimentation, blood calcium, urine calcium, calcitonin, etc. if necessary. 6. Ask for otorhinolaryngology consultation to check the position and function of vocal cords. 7. Pay attention to the differentiation of malignant tumor from chronic thyroiditis and nodular goiter, etc. If necessary, perform fine needle aspiration cytology or surgical biopsy.