Deep vein thrombosis (DVT) is a common clinical disease, and pulmonary embolism (PE) is the most serious complication of DVT. However, it should be clarified that vena cava filters are not routinely used as a treatment for lower extremity DVT, and their use is subject to certain indications. At present, the indications for clinical application of vena cava filters in DVT patients internationally include absolute and relative indications. Absolute indications include: (1) patients with VTE who are contraindicated by anticoagulation but have been diagnosed; (2) patients with VTE who have complications from anticoagulation; (3) patients with VTE who have failed anticoagulation; (4) patients who have PE despite adequate anticoagulation. Relative indications include: (1) Large isolated floating iliofemoral vein thrombosis. (2) Patients with DVT who have poor cardiopulmonary reserve. (3) Patients with DVT who have had prior pulmonary embolism. (4) Iliofemoral vein thrombosis treated with thrombolysis or embolization. (5) Acute iliofemoral thrombosis Patients who are to undergo major surgery. (6)Patients with potential anticoagulation complications, such as severe anemia, shock, trauma combined with DVT.