In recent years, the incidence of thyroid nodules has gradually increased, especially with the development and popularization of high-frequency ultrasound, the detection rate of thyroid nodules is as high as 19%-67%, among which the proportion of thyroid cancer is about 5%-15%. So, when a thyroid nodule is found, how should one distinguish whether it is benign or malignant? Ultrasound is the most sensitive and cost-effective way to determine the nature of thyroid nodules. Under high-frequency ultrasound detection, it can clearly show the size, texture, echo intensity, shape, edges, calcification, blood flow and other information of the nodule. By recognizing the external features of the “suspects”, experienced doctors can basically determine whether the nodule is a benign or a malignant nodule. “or” thug “to make a preliminary judgment. So, what are the characteristics of these “undesirable elements”? Among these characteristics, the three most specific signs of malignancy are microcalcification, irregular margins and aspect ratio greater than 1, and their diagnostic specificity for malignancy reaches 87.8%, 83.1% and 96.6% respectively.