Lower extremity deep vein thrombosis (DVT): The clinical features of lower extremity DVT are severe lower extremity swelling, increased calf muscle tone, swelling, pressure pain, red skin color, and significantly increased skin temperature. Stagnant venous blood flow, increased blood viscosity and venous injury are the main causes of this disease. It is mostly seen in prolonged bed rest, fracture, surgery or prolonged car or airplane travel, etc. Lack of limb activity causes stagnant blood flow in the deep veins of lower limbs. The main dangerous complication of lower limb deep vein thrombosis is pulmonary artery embolism, which is life-threatening once it occurs. Therefore, deep vein thrombosis should be treated actively in the acute stage, and bed rest should be taken to avoid thrombus dislodgement caused by strenuous activities of the affected limbs, leading to pulmonary embolism. The main treatment methods for DVT are thrombolysis, anticoagulation and surgery. For patients with acute lower limb DVT who have had pulmonary embolism or are at risk of pulmonary embolism, inferior vena cava filter implantation is a better way to prevent pulmonary embolism and protect life. Inferior vena cava filters are divided into temporary and permanent filters, and the choice of temporary or permanent filters is based on the duration of the patient’s onset factors and the patient’s age.