Category 2 thyroid nodules are classified by TI-RADS in ultrasonography. Category 2 indicates benign nodules with a probability of malignancy of 0. If the nodules do not continue to develop on regular review, they will not become malignant. Thyroid nodules are classified by TI-RADS on ultrasound according to the size of the nodule, whether the border is clear, whether there is calcification, the type of calcification and other manifestations, and are generally classified into 5 categories. If the nodule changes during the follow-up, the risk of malignancy may increase and further puncture is needed to clarify. If they do not change, they are generally not likely to become malignant. In conclusion, thyroid nodules are mostly benign nodules and do not require medication, but must be followed up regularly. Patients with malignant thyroid nodules can also have a better prognosis after early detection and timely treatment.