Pulmonary embolism is one of the serious complications of lower extremity deep vein thrombosis, which can lead to death in severe cases. By placing a vena cava filter in the inferior vena cava to intercept the dislodged thrombus in the lower extremity and prevent it from entering the pulmonary artery and leading to pulmonary embolism, thus preventing pulmonary embolism, filter implantation is an effective treatment to prevent severe pulmonary embolism due to lower extremity DVT. The basic treatment for lower extremity DVT is anticoagulation therapy. For the existence of contraindications to anticoagulation therapy, such as: after major surgery, the existence of bleeding, etc., in addition, before performing venous dissection for embolism, mechanical embolism, catheter thrombolysis, or the patient has already had a pulmonary embolism to prevent further aggravation can prevent the inferior vena cava filter. There is no rejection after filter implantation, but it has been reported that permanent filter placement increases the chance of recurrent lower extremity venous thrombosis and vena cava thrombosis, mainly because filter implantation can lead to sub-filter thrombosis. The need for long-term anticoagulation therapy such as oral warfarin after filter implantation is currently the subject of much debate and there is no unified statement to date. We advocate long-term warfarin anticoagulation therapy to prevent sub-filter thrombosis after filter implantation if the patient’s condition allows, e.g., no contraindications to long-term anticoagulation and good compliance, provided that coagulation function is regularly reviewed. There are no studies on the adverse effects of smoking on the vena cava filter after implantation, but it is recommended to quit smoking because of its harmful effects on the circulatory system. There are no special requirements for diet and exercise. If you feel any increase in swelling of the lower limbs or pain in the lower back after filter implantation, you can follow up with a specialist to check the ultrasound or even CT of the inferior vena cava to determine whether there is any thrombosis in the inferior vena cava, and whether there is any abnormality in the location and shape of the filter.