Thyroid carcinoma (TC), a cancer of the thyroid gland, accounts for about 1% of all malignant tumors in humans, with an annual incidence of about 1.5/100,000. Since the leakage of Chernobyl nuclear power plant in the former Soviet Union in the mid-1980s, thyroid cancer is the fastest growing solid malignant tumor in the past 20 years, with an average annual growth rate of about 6.2%. Currently, it is the 5th most common malignant tumor in women. Thyroid microcarcinoma (TMC) is a type of thyroid cancer less than 1 cm in diameter. In recent years, with the development and improvement of high-frequency ultrasound and pathological diagnosis technology, the incidence and examination rate of TMC has increased significantly. Because of its small size and insidious onset, microscopic thyroid cancer is often co-existing with other thyroid diseases, so it is more often missed and misdiagnosed during clinical examination. The original reports on TMC are relatively few, mostly found in autopsy reports, and the detection rate reported abroad is 5.6~35.6%. In recent years, with the development and improvement of high-frequency ultrasound and pathological diagnostic techniques, the incidence and examination rate of TMC has increased significantly, and now it is reported to account for about 21.7%-49% of all thyroid cancers. With the progressive study of TMC, it is found that TMC has an insidious onset and can be a subclinical state without progression for a long time, and coexists with other thyroid diseases. Therefore, there is a great controversy about the risk, treatment and value of its treatment both nationally and internationally.