Ultrasound is the first choice for thyroid cancer diagnosis. Ultrasound is usually used in black and white, color ultrasound, flexible ultrasound, ultrasonography, and ultrasound-guided puncture and intervention. Usually, the first thing a patient does when he comes in is to give him an ultrasound examination of the thyroid gland, and each different tumor has a different grading, generally speaking, using the TI-RADS analysis method. Generally speaking, the thyroid is divided into four types of tumors, papillary carcinoma, follicular carcinoma, medullary carcinoma and undifferentiated carcinoma. The ultrasound presentation of each of them is different. Usually, more than 90% of them are papillary carcinoma, which is mainly a localized hypoechoic mass with unclear borders and uneven internal echogenicity, and may have sandy calcification in part, and the blood vessels are mainly of central type. Another point that is relatively specific is that the aspect ratio is greater than 1, that is, the ultrasound shows that the mass is standing up and growing, in this case, thyroid cancer is considered more often. Ultrasound has advantages over CT and MRI for thyroid cancer, so the first choice for thyroid examination is usually ultrasound, and CT has certain advantages over ultrasound for the diagnosis of lymph nodes in the neck. The most important thing is that the surgeon can understand the CT film and can see the surrounding lymph nodes in other parts of the neck; MRI is rarely used in thyroid.