Objective: To investigate the efficacy of early detection and intervention in borderline lower-limb deep venous thrombosis (DVT). Methods: The clinical data of 23 patients with borderline lower-limb DVT were retrospectively analyzed. All the patients were confirmed having positive "snowstorm sign" in the deep veins of lower limb by duplex ultrasonography, and the central velocity of axial blood flow of femoral and popliteal veins as well as the center of snowstorm sign of the patients was measured. These hemodynamic parameters before and after treatment were compared to determine the therapeutic effect. Results: All patients were discharged from hospital after basic anticoagulation, antiplatelet and volume expansion therapy for five to seven days. The peak velocity of femoral and popliteal venous axial blood flow of the patients increased after treatment (all P＜0.01), and their snowstorm signs disappeared or lessened. Conclusions: Duplex ultrasonography screening for early detection and intervention of borderline low-limb DVT is helpful to prevent the thrombus converting to a solid state, and it thereby avoids surgical intervention (such as thrombus and inferior vena cava filter implantation) and the risks and adverse effects of long-term anticoagulation and/or thrombolysis.