To analyze the application value of ATA guidelines, ACR TI-RADS classification and C-TIRADS classification in the differential diagnosis of thyroid nodules. Methods238 patients with thyroid nodules (265 nodules) were selected for routine ultrasound examination and statistical analysis. The nodules were classified and diagnosed according to ATA, ACR TI-RADS and C-TIRADS and the pathological results were used as the gold standard to draw ROC curve to predict the diagnostic value of the three methods. ResultsAmong 265 thyroid nodules, benign nodules were 128(48.30%) and malignant nodules were 137(51.70%). The sensitivity of ATA, ACR TI-RADS and C-TIRADS is 97.81%, 94.19% and 91.24% respectively, and the area under the curve is 0.807,0.815 and 0.905 respectively. The diagnostic efficiency of C-TIRADS is higher than that of ATA and ACR TI-RADS classification standards. ConclusionThe three classification methods have certain diagnostic value for thyroid nodules, and C-TIRADS has a broad application prospect in clinical practice.