Given the high mortality rate of pulmonary embolism, prevention of the disease becomes even more important. The two points to be grasped in preventing pulmonary embolism are to prevent all kinds of emboli and to prevent emboli from entering the pulmonary artery. The primary measure is to increase the blood flow velocity in the limbs and reduce blood stagnation in the lower limbs, thus reducing the formation of venous thrombosis. For the elderly, obese people, tumor patients and other people with high risk factors for thrombosis, they should move frequently on weekdays and not keep a fixed sitting position for too long. Long-distance travelers should regularly get up and move their lower limbs, don’t sit for a long time; when sitting in long-distance airplane or other transportation, untie the shoelaces or wear slippers, which can reduce the local vascular compression on the ankle and reduce the lower limb edema. Patients with varicose veins can wear compression elastic stockings and sit down regularly to elevate their legs after standing for a long time, which is conducive to lower limb blood flow back. For those who must be bedridden for a long time after trauma or surgery, they can use compression elastic stockings or elastic bandages, do inflatable massage of lower limbs regularly, and also do prophylactic anticoagulation therapy under the supervision of doctors; meanwhile, patients are urged to turn over regularly, and those who can move on their own but cannot get out of bed, try to move the knee and ankle joints of lower limbs by themselves and take the initiative to do muscle exercise; for those who cannot move on their own, family members should do muscle massage of limbs daily. This can accelerate the venous blood flow in the lower limbs, which is effective in preventing deep vein thrombosis in the lower limbs. If there is asymmetric swelling of the lower limbs, it should be taken seriously and go to the hospital for further examination. Those who have already formed thrombosis should use anticoagulant drugs, such as Speedy Bilin, aspirin and Pansentine.