Objective: To explore the diagnostic efficacy of ultrasound elastography in the staging of deep venous thrombosis of lower extremities. Methods: A total of 110 patients with deep venous thrombosis of lower limbs admitted to our hospital from January 2020 to June 2022 (observation group) and 100 healthy subjects (control group) during the same period were selected as the study objects, and all of them received ultrasound elastography examination. The results of ultrasonic elastic imaging were compared between the two groups. Logistic regression analysis was used to analyze the relationship between various indicators of ultrasonic elastic imaging and the staging of lower extremity deep vein thrombosis, and Pearson correlation analysis was used to analyze the relationship between elastic imaging and laboratory parameters. Receiver operating characteristic (ROC) curve was plotted to analyze the diagnostic efficacy of ultrasound elastography in staging of deep venous thrombosis of lower extremities. Results: The proportion of thrombus detection and ultrasound elasticity score in the observation group were higher than those in the control group, and the differences were statistically significant (P<0.05). The mean value of ultrasonic elasticity score and Young''s modulus of patients in acute stage were lower than those in subacute stage and chronic stage. Logistic regression analysis showed that the increase of ultrasonic elasticity score and mean Young''s modulus were the influencing factors for the development of lower limb deep vein thrombosis in chronic stage (P<0.05). Pearson correlation showed that the ultrasonic elasticity score was negatively correlated with aPTT, PT and Fbg (r=-0.411, -0.484, -0.667, P<0.05). The mean value of Young''s modulus was negatively correlated with aPTT, PT and Fbg (r=-0.426, -0.506, -0.712, P<0.05). According to the ROC curve analysis, the AUC (0.891, 95%CI:0.795~0.987) of ultrasonic elastic imaging (ultrasonic elastic score combined with the mean value of Young''s modulus) in diagnosing the stage of deep vein thrombosis of lower limbs was the largest, and the sensitivity and specificity were 93.33% and 95.00%, respectively(P<0.05).