Inclusion Criteria:  Patients sign the informed consent form for participating in the reasearch study. Patient's age is 18 years or older. Ultrasound showed at least one thyroid nodule, and it was classified as C-TIRADS Category 3/4a. The surgeon has evaluated the indications for surgery, and the subject is willing to receive surgical intervention in the medical institution. Surgical indications include but are not limited to one of the following conditions: 1) Thyroid nodules are compressed or affect aesthetics; 2) The patient's subjective wishes require surgical removal of the nodules; 3) FNA samples with indeterminate cytology are classified as Bethesda III and IV, requiring diagnostic surgery; 4) After the investigator's assessment, there are other surgical indications. Preoperative FNAB to obtain sufficient cells to meet FNA samples with indeterminate cytology are classified as Bethesda III and IV. The final pathological diagnosis is obtained after surgury.  Exclusion Criteria:  The subject has a history of thyroid tumor. The subject has swollen lymph nodes in the central area or/and lateral neck area. The subject is not suitable for fine-needle aspiration biopsy and surgical treatment due to other conditions such as comorbid diseases. FNAB interprets the thyroid nodule as Bethesda V and VI categories. Subjects who intend to receive the radiofrequency ablation therapy. Other conditions determined by the researcher that do not meet the criteria of enrollment.