Thrombosis refers to the abnormal coagulation of blood in blood vessels, which is prone to thrombus formation. The three factors of thrombosis mainly include damage to the vessel wall, changes in blood flow status, and abnormal coagulation factors, which can lead to thrombosis if any one of them is in trouble. Common clinical risk factors for thrombosis include surgery, lower limb braking, and blood transfusion, malignant tumors, and long-term bedridden patients, all of which are prone to secondary thrombosis. Clinical tests of patients with elevated D-dimer after thrombosis, and ultrasound suggestive of thrombosis, all of which can lead to a clear diagnosis. Patients can wear lower extremity compression stockings, eat drugs to improve venous function, as well as early functional exercise, can effectively prevent thrombosis.