Each patient’s condition and diagnosis and treatment vary, and the time to reduce the swelling of the leg from venous thrombosis varies. It mainly depends on the location and extent of the thrombus, the time of its formation and whether the treatment is timely and standardized. If the diagnosis is timely and the treatment is proper, the swelling can be significantly reduced in about a week. The swelling of calf deep vein thrombosis is generally limited to the calf and is mild. As long as this kind of thrombosis can be treated in a timely and standardized manner in the hospital, the swelling can be reduced and healed soon. Proximal deep vein thrombosis such as iliac vein thrombosis, leg swelling is more serious, generally the whole lower limb can appear obvious swelling, then the choice of treatment plan is more important. Conservative treatment such as anticoagulation is slow to reduce leg swelling, usually taking 2-4 weeks or longer. If the catheter is placed directly on the thrombus site for thrombolysis in time, the effect is better, and the swelling can be significantly reduced within a week. If the current mechanical thrombosis drug thrombectomy is chosen to quickly remove the thrombus, reduce the thrombus load, lift the obvious stenosis or occlusive lesion, and achieve one-stop treatment, the edema can significantly subside immediately after the procedure. If deep vein thrombosis is not effectively treated in time, post-deep vein thrombosis syndrome occurs, which will cause leg swelling repeatedly difficult to subside. Swelling and pain after walking for a longer period of time, leg swelling increases and is difficult to return to normal. It will inevitably bring obvious effects to patients, leading to impaired quality of life and work ability.