The incidence of deep vein thrombosis (DVT) after traumatic fracture is high, and DVT causes serious adverse effects on the postoperative recovery of patients. The purpose of this study was to explore the effect of coagulation-related indicators combined with vascular ultrasound measurements for the risk assessment of DVT after secondary traumatic fracture, and to provide a new method for predicting the occurrence of DVT. The clinical data of patients with secondary traumatic fracture surgery in our hospital from January 2019 to January 2022 were retrospectively analyzed. The patients were divided into a non-DVT group and a DVT group according to whether DVT was indicated in the medical record system. The coagulation-related indices and vascular ultrasound measurements of the two groups were compared, and the risk factors for postoperative DVT were analyzed by bivariate correlation and multivariate logistic regression. According to the medical record system, 55 patients (47.41%) had DVT, and 61 patients (52.59%) did not have DVT. There was no significant difference in prothrombin time (PT) or activated partial thromboplastin time (APTT) between the two groups (p > 0.05). The thrombin time (TT) in the DVT group was lower than that in the non-DVT group. The levels of fibrinogen (FIB) and D-dimer (D-D) in the DVT group were higher than those in the non-DVT group (t = 2.766, 3.242, 2.649, p = 0.007, 0.002, 0.009). Spearman correlation analysis showed that peak systolic velocity (Vs), end-diastolic velocity (Vd), pulsatility index (PI), resistance index (RI), FIB, and D-D were positively correlated with the risk of DVT after secondary traumatic fracture surgery (r = 0.264, 0.656, 0.293, 0.276, 0.287, 0.251, p < 0.05). TT was negatively correlated with DVT risk after secondary traumatic fracture surgery (r = -0.249, p < 0.05). The measurements of peak systolic velocity (Vs), end diastolic velocity (Vd), pulsatility index (PI) and resistance index (RI) in the DVT group were higher than those in the non-DVT group (t = 2.663, 2.998, 3.135, 2.953, p = 0.009, 0.003, 0.002, 0.004). FIB, D-D, Vs, Vd, PI, and RI were independent risk factors for DVT after secondary traumatic fracture surgery (Odds Ratio (OR) = 1.483, 2.026, 2.208, 1.893, 1.820, 1.644, p < 0.05). TT index was an independent protective factor for DVT after secondary traumatic fracture surgery (OR = 0.868, p < 0.05). The sensitivity and specificity for prediction of DVT based on combined coagulation-related indicators and vascular ultrasound imaging measurements were higher than those of individual measurements (p < 0.05). Coagulation-related indicators and vascular ultrasound parameters can effectively predict the formation of DVT. Through the analysis of factors related to DVT formation, screening of high-risk patients for effective intervention may help to reduce the risk of DVT. Further verification in additional, large-scale clinical trials is advocated.