Vena cava filters are safe and effective in the prevention of pulmonary thromboembolism and are necessary for the implantation of vena cava filters in patients with deep vein thrombosis of the lower extremities in order to prevent pulmonary thromboembolism. Deep vein thrombosis occurs in older, obese, and sedentary people, and some other diseases are also prone to deep vein thrombosis, such as thrombophlebitis and varicose veins; general surgery, orthopedics, obstetrics and gynecology under general anesthesia for more than 30 minutes, malignant tumors, pregnancy and contraceptive pills, and certain prothrombin deficiency disorders. In this regard, we remind everyone that people who operate computers for a long time and those who are expected to sit in airplanes, cars, trains and boats for a long time (more than 6 hours) must be highly alert to the occurrence of venous thrombosis. Pay attention to the following 4 points: 1, wear loose clothes and shoes and socks, especially the lower limbs or waist clothes should not be too tight. 2, get up every once in a while and walk around, often do whole body especially leg activities, such as moving the ankle. 3.Drink more water, do not smoke, and avoid alcoholic or caffeinated drinks. 4.Once the swelling of lower limbs occurs, go to the hospital for examination in time. Total diet control: drink soup first, then eat, 80% full is fine. Start from changing your lifestyle to reduce the risk factors of thrombosis. Diet structure adjustment: don’t be too sweet, not too salty, not too greasy. Quit smoking, drink less, and exercise more. Avoid being overweight or obese starting in childhood.