Ultrasound is a non-invasive diagnostic method. The thyroid gland is superficially located and its anatomy is different from the surrounding tissues. High-frequency ultrasound has good resolution of thyroid lesions and can visually determine the site, size and number of thyroid masses as well as the internal echogenicity. Thyroid calcifications are usually classified by size into gross calcifications ≥2 mm and microcalcifications <2 mm. On pathologic histology, thyroid calcifications are divided into two types: sandy microsomes and dystrophic calcifications. Sandy granules are often a feature of papillary thyroid carcinoma, but can sometimes be seen in other types of thyroid cancer and benign lesions such as follicular carcinoma, nodular goiter, follicular adenoma, and Hashimoto's thyroiditis. Dystrophic calcification is mainly due to excessive tissue proliferation and calcium salt deposition resulting in calcification, mostly seen in benign lesions, with about 10-20% being cancerous, with follicular adenocarcinoma accounting for a larger proportion. Microcalcifications in the thyroid gland basically respond to the sand granules in the pathology and have high specificity for the diagnosis of thyroid cancer. The new staging criteria of the International Union Against Cancer for differentiated thyroid carcinoma consider that the prognosis of the two groups before and after the age of 45 is obviously different. Therefore, we analyzed whether there was a difference in the incidence of benign and malignant calcified nodules between different age groups using 45 years as the boundary, and the statistical result P=0.002 showed a significant difference, indicating that young patients (<45 years old) with calcified thyroid nodules should be highly alert to the possibility of malignancy. For patients with calcified thyroid nodules detected by ultrasonography, especially microcalcifications or single nodule calcifications, clinicians should be vigilant, carefully examine and monitor them, and operate them as early as possible to reduce the missed diagnosis and misdiagnosis of malignant thyroid tumors.