Leg swelling caused by thrombosis is mainly caused by venous thrombosis blocking the lower extremity venous blood return pathway, causing lower extremity venous return obstruction, resulting in lower extremity venous stasis and leg swelling. Anticoagulation therapy includes subcutaneous injection of low molecular weight heparin, or oral anticoagulation therapy with warfarin, rivaroxaban, dabigatran and other drugs. Decongestion therapy mainly consists of oral administration of horse chestnut seed extract, calcium hydroxybenzene sulfonate capsules, diosmin tablets, mai zhi ling tablets and so on to improve the swelling of lower limbs by improving vascular permeability and promoting venous reflux. It can also be combined with the wearing of varicose veins stockings in the lower extremities to promote venous return and reduce edema of the tissues. In addition to the above treatments, it is also necessary to avoid prolonged standing or sitting in daily life and avoid heavy physical work. When leg swelling caused by thrombosis occurs, it is recommended to make a clear diagnosis under the guidance of a specialist and choose the appropriate method of treatment.