Thyroid cancer is the most common malignant tumor of the endocrine system, accounting for the first place in the incidence of head and neck malignant tumors and about 1% of the whole body malignant tumors. 7% to 21% of the population can be palpable thyroid nodules, of which about 5% are thyroid cancer, and the trend is increasing in recent years. Early diagnosis of thyroid cancer is important in deciding the surgical procedure and improving the prognosis and prolonging the survival of patients. Malignant nodules should be suspected when the following sonographic features are present, and the more features that match, the greater the possibility of malignancy: 1. hypoechoic or very hypoechoic; 2. irregular border without envelope; 3. irregular sound halo with variable thickness; 4. aspect ratio greater than 1; 5. microcalcifications inside; 6. posterior echogenic attenuation; 7. central vascular type; 8. male. Thyroid nodules are painless, without obvious symptoms and not easy to detect. The thyroid gland is located on both sides of the trachea, dorsal to the esophageal nerve and flanked by the arteries and veins, thyroid cancer nodules are easy to invade with the above organs, resulting in incomplete surgical resection, so early detection of thyroid nodules is important and routine thyroid ultrasound is needed. With the widespread use of high-resolution high-frequency ultrasound and color Doppler flow imaging technology, the compliance rate of ultrasound diagnosis of thyroid disease has gradually increased. As a non-invasive, non-painful, non-radioactive, high-resolution and high-accuracy examination method, high-frequency ultrasound has become the preferred examination method for thyroid cancer.