Anticoagulation therapy is the basic treatment for patients with lower extremity DVT. According to different treatment periods and purposes, anticoagulation therapy can be divided into short-term period anticoagulation and long-term anticoagulation. The purpose of short-term anticoagulation is to prevent the continuous spread of already formed thrombi, and the most used drug in clinical practice is heparin. Historically, continuous intravenous administration of heparin was the classic short-term anticoagulation therapy, but this approach has several drawbacks. First, patients have to receive continuous drug injections for up to 3 or 4 days, which seriously affects life therapy; second, some patients can experience heparin resistance, leading to reduced clinical efficacy, and for some patients with renal insufficiency, continuous heparin use is also unsafe; finally, continuous heparin use requires constant monitoring of coagulation indicators such as APTT, which does not have a standard for uniform reagents and often There is no standardized reagent for APTT, which often results in poor outcomes despite meeting treatment standards. This has caused a lot of problems for patients and physicians. Therefore, it is currently less used in clinical practice. Therefore, since the 1990s, scholars have been working on the development of new heparins. The more ideal heparin should have the following characteristics: 1) easy administration method; 2) long drug half-life, so that it only needs to be given once or twice a day; 3) less influence on coagulation index; 4) satisfactory anticoagulation effect. Through unremitting efforts, low-molecular heparin eventually emerged. At present, low-molecular heparin has been accepted by the vast majority of physicians as the drug of choice for short-term treatment. Immediate anticoagulation with low-molecular heparin alone is not sufficient; in many cases, the risk factors for lower extremity deep vein thrombosis are difficult to eliminate completely, so there is a risk of distant recurrence and a corresponding need for long-term anticoagulation. Since low-molecular heparin is more expensive, it is difficult to adhere to long-term use, and currently the main clinical use is to use warfarin as the representative of the double coumarin class of drugs. For general patients with lower extremity DVT, ACCP recommends long-term anticoagulation for 3 to 6 months. For certain patients with abnormal coagulation mechanisms and other high-risk factors, lifelong anticoagulation is recommended. For patients at risk for anticoagulation, other treatments such as lower vena cava filter implantation are recommended. Anticoagulation is associated with certain risks, including heparin-induced thrombocytopenia, bleeding from the skin mucosa, gastrointestinal tract, urinary tract, and even intracranial sites, to name a few. This often puts anticoagulation therapy in a dilemma: if the drug dose is insufficient, a satisfactory therapeutic effect cannot be achieved; and in case the dose is excessive, the risk of bleeding is greatly increased and can even be life-threatening. Therefore, a formal, professional anticoagulation regimen should be developed at the outset by a vascular surgeon based on the patient’s individual situation (thrombotic risk factors, general health, lifestyle, etc.). During the anticoagulation process, the vascular surgeon will also test the coagulation parameters according to the patient’s condition and will continuously adjust the medication according to the test results.