Objective：To evaluate the accuracy of the SurePath - liquid based cytology（SurePath - LBC）technique in the cytopathological dignosis of fine needle aspiration（FNA）for thyroid nodules. Methods：A retrospective study was conducted on 352 patients（363 thyroid nodules）from the Thyroid and Breast Surgery Department of the First Affiliated Hospital of Nanjing Medical University，who underwent thyroidectomy and had complete preoperative cytopathological and postoperative pathological data. The SurePath -LBC was used for cytological diagnosis before surgery，and the cytopathological diagnoses were compared with the surgical pathology results. 363 independent cytology reports were obtained from these patients. BRAF^V600E mutation testing was also performed on 264 cases. Results：Cytopathology suggested suspicious for malignancy（SM）in a total of 112 cases，including 110 cases of suspected papillary thyroid carcinoma（PTC）and 2 cases of suspected medullary thyroid carcinoma（MTC）. Among the 110 suspected PTC cases，surgical pathology confirmed 106 cases as PTC，1 case as atypical adenoma，1 case as follicular thyroid carcinoma（FTC）， and 2 cases as well differentiated tumors of uncertain malignant potential（WT-UMP），with a diagnosis accuracy of 96.4%. Both cases suspicious for MTC were confirmed as MTC by surgical pathology，with an accuracy of 100.0%. The overall accuracy for SM cases with surgical pathology was 97.3%. 211 nodules were reported as“malignant，M”（210 PTC and 1 case MTC）. Among 210 PTC cases，209 cases were confirmed by histology，and 1 case was confirmed to be atypical adenoma，yielding a diagnosis accuracy of 99.5%. The case diagnosed as MTC by cytology was also confirmed as MTC by surgical pathology，with a diagnosis accuracy of 100.0%. The overall diagnosis accuracy for suspected M cases with surgical pathology was 99.5%. The BRAF^V600E mutation rates of SM and M cases were 82.3% and 95.5%，respectively. Among the seven nodules cytologically diagnosed as benign，final surgical pathology revealed 3 cases of nodular goiter，2 cases of follicular tumors，and 2 cases of PTC. There were 23 thyroid nodules reported as atypia of undetermined significance（AUS），19 cases of which were classified ase TI-RADS 4B or higer，with a BRAF^V600E mutation rate of 62.5%（10/16）and an overall malignancy rate of 87.0%. In the 10 cases with nondiagnostic（ND）results，the BRAF^V600E mutation rate was 57.1%（4/7）， with an overall malignancy rate of 50.0%. Conclusion：The SurePath -LBC method for preparing cytological specimens from thyroid FNA for the diagnosis of SM or M showed high concordance with surgical pathological diagnosis. It is also accurately indicated specific malignancy types. This technique has significant reference value for the preoperative diagnosis of thyroid nodules and is worth further promotion and application.