〔Abstract〕 Objective To establish an assessment model for predicting the aggressiveness of papillary thyroid microcarcinoma(PTMC) and to provide a theoretical basis for actively monitoring the same. Methods 264 PTMC patients were included from October 2017 to January 2021. All patients were confirmed by postoperative pathology. 154 cases collected from October 2017 to April 2019 were included in the model group while 110 cases collected from May 2019 to January 2021 were included in the validation group. We analyzed the clinical data, ultrasound characteristics, and BRAF V600 E gene status of 154 patients in the model group with confirmed PTMC based on pathological examination. Single factor regression was used to screen out risk factors for PTMC invasion, and these factors were then included in a multivariate logistic regression analysis to establish a risk prediction model; the established model was used to evaluate the diagnostic efficacy of 110 PTMC patients in the validation group. Results Multivariate analysis showed that male sex, age<45 years, microcalcification, tumor diameter>5 mm, suspected extraglandular invasion and lymph node metastasis on ultrasound, and BRAF V600 E gene mutation were all risk factors for PTMC invasion. A scoring model was established according to risk factors, and the higher the score, the higher the risk. In the 110-case verification group, the area under the predictive performance curve of the evaluation prediction model was 0.774(95%CI: 0.685-0.848), the cut-off value was 0.450 2, the sensitivity was 83.3%, and the specificity was 62.9%. The model therefore had good diagnostic efficacy. Conclusion Ultrasound combined with BRAF V600 E gene detection model can predict the aggressiveness of PTMC to a certain extent, which can provide reference for the selection of clinical treatment options.