Leg vein thrombosis after four years and then swollen, indicating that the patient’s lower extremity venous thrombosis caused by reflux obstruction, feasible surgical treatment or conservative treatment. 1. Surgical treatment Surgery is mainly applied to patients with urgent condition of lower extremity venous thrombosis, commonly used microcatheter thrombolysis or catheter suction treatment, which can remove most of the thrombus in the patient’s venous blood vessels, and deal with the venous thrombosis quickly, and need to take anticoagulant drugs, such as rivaroxaban and so on, and suggest the patients to have regular review after the operation, usually after 3~6 months to review the ultrasound of the lower extremities. 2. Conservative treatment If the patient has been suffering from the disease for a long time and has formed fixed plaques in the veins, then the surgical treatment does not have a more ideal effect, and the patient needs to be treated with conservative treatment, including the promotion of venous reflux and oral anticoagulant drugs. (1) Promote venous return. Anti varicose vein stockings can be worn in daily work and life in order to reduce the pressure of the patient’s lower limb veins. (2) Oral anticoagulant drugs. Commonly used anticoagulant drugs include warfarin sodium tablets, rivaroxaban tablets and so on. It is recommended that patients take medication regularly under the guidance of doctors and do not use them on their own. Patients are advised to avoid standing or sitting for a long time, and to exercise appropriately. Patients with lower extremity venous thrombosis should be reviewed regularly after treatment.