The incidence of thyroid cancer has been on the rise in recent years, but it has been recognized that most treatments for thyroid cancer are very effective and the long-term outcome is more satisfactory. How to detect and treat it early is very crucial. How to detect early? The means is the use of color ultrasound. At present, high-frequency head color ultrasound examination can detect masses of 2 mm or more. Together with the widespread use of ultrasound-guided thyroid swelling puncture fine needle technique, tiny thyroid cancers smaller than 1 cm have been detected in large numbers. Therefore, ultrasonography is a highly specific, non-invasive, painless and repeatable examination method. In addition, CT and MRI are mainly used for the second line of examination after finding the mass. It is mainly used to understand the relationship between the tissues and organs surrounding the thyroid mass, such as whether the surrounding invades the trachea, esophagus and large blood vessels in the neck, and whether there is any tissue and organ invasion in the neck. Nuclear scan is used to understand the iodine absorption function of the thyroid swelling and to determine the type of nodule. They are classified as cold vs. cool, warm vs. hot nodules. It is suggestive for benign and malignant. However, qualitative diagnosis of thyroid cancer is difficult. Therefore, the examination of thyroid by high-frequency head ultrasound has high specificity and non-invasive and repeatable. Therefore, the examination of high frequency head of ultrasound is necessary at present.