Objective: To explore the diagnostic value of thyroid image report and data system (TI-RADS) for papillary carcinoma in the background of Hashimoto''s thyroiditis (HT) by conventional ultrasound classification, ultrasound elastography(UE) and ultrasound contrast(CU) enhanced ultrasound multimodal ultrasound imaging score. Confirmed by pathological methods: select 310 patients with HT merged thyroid nodule, a total of 339 nodules, line of TI - RADS classification, UE and CU, according to the result can be divided into benign nodules and PTC group, on two groups of nodes in a single diagnosis method and the result of combined application of grade distribution comparison, using ROC curve under the background of hashimoto papillary carcinoma diagnosis efficiency analysis and determine the cut-off value. Results: There were statistically significant differences in the single diagnosis method and the combined application of the three methods between the benign nodular group and the PTC group (P < 0.05). Under ROC curve, the AUC and diagnostic efficiency of multimodal ultrasound for papillary carcinoma were significantly higher than that of single diagnosis method (P < 0.05). Conclusion: Multimodal ultrasonography can improve the diagnostic efficiency of PTC in the background of HT. 9.5 The cut-off point values of benign nodules and PTC.