Deep vein thrombosis of the lower extremity is a common and frequent clinical disease, and with the continuous improvement of people’s living standard, the incidence of this disease is still on the rising trend in recent years. Traditional diagnostic methods such as color Doppler ultrasound and conservative thrombolytic therapy are far from satisfying the needs of patients due to their poor effects. In recent years, through the joint efforts of domestic and foreign vascular surgery experts for nearly ten years, a new treatment strategy has emerged, and thousands of patients with venous thrombosis have become beneficiaries. Deep vein thrombosis of the lower extremity is a disease characterized by sudden swelling and pain of the lower extremity (left lower extremity is common), purple or flushed extremity, and aggravation of symptoms after standing and moving. In the early stage, it is easy to cause sudden death due to pulmonary embolism or necrosis of the limb due to fast development of thrombus, and in the later stage, it is easy to form ulcer in the foot and shoe area, deep vein valve insufficiency and superficial varicose veins, which is known as an extremely critical and difficult disease in vascular surgery. The traditional treatment method lacks specificity in diagnosis, and it is not easy to diagnose the length, location, freshness or obsolescence of thrombus; in treatment, there are problems such as low rate of complete recanalization, incomplete thrombolysis and easy recurrence, so the clinical treatment effect of this disease is often unsatisfactory in the past, but the new treatment strategy can solve the above problems well. Mainly in the following two aspects: 1. Diagnosis: Color Doppler ultrasound is the preferred means of examination for patients with lower extremity deep vein thrombosis, but the proficiency and experience of color ultrasound examiners will have a great impact on the ultrasound results, and it cannot make a clinically ideal diagnosis for patients who need surgery in the late or acute stage. With the continuous improvement of MRI equipment, the objective accuracy of non-invasive lower extremity venous MRI in diagnosing the site, nature and extent of venous thrombosis has been greatly improved, which provides a reliable basis for vascular surgeons to carry out interventional and surgical treatment. Another kind of venous angiography is intravascular imaging, whose results are true and reliable, and is an indispensable beacon light in the process of venous thrombosis extraction, interventional treatment and surgical bypass. In addition, pulmonary nuclear scan has authoritative conclusion on whether the complication of pulmonary embolism; platelet count in blood, coagulation four, D-dimer test are also the main laboratory test indicators of the disease. The combination of the above diagnostic methods can make accurate diagnosis of lower limb deep vein thrombosis, and provide great help for clinical treatment to choose the adapted treatment method. 2, conservative thrombolysis: treatment is the main traditional treatment method of the disease, many hospitals can’t carry out the international standard anticoagulation thrombolysis method well due to the lack of coagulation system monitoring, plus the local drug infusion conditions are not available, so that the early thrombosis of this kind of patients can’t dissolve as soon as possible, and the later recovery is not ideal. Those who cannot tolerate surgery or do not have the conditions should use intervention. Interventional placement of thrombolysis can be used for patients within 1 month of onset of disease, and local continuous infusion of international standard thrombolytic and anticoagulant drugs by inserting a special thrombolytic catheter is the preferred treatment method, which is less damaging and more effective, and more suitable for the old and frail. In the case of old lower limb deep vein thrombosis after several months, surgical bypass or intermittent treatment with bionic air pressure instrument and combined Chinese and Western medicine methods to promote the establishment of collateral circulation can be chosen as the goal. According to clinical reports, the treatment of lower extremity deep vein thrombosis by the above methods has achieved very satisfactory therapeutic results. The prevention of lower limb deep vein thrombosis should be mobilized by all people to raise the awareness of prevention. For people with high blood viscosity who keep standing or sitting for a long time should pat their legs frequently, exercise intermittently or wear preventive elastic stockings. For patients who are bedridden for a long time after surgery or fracture should pay attention to elevate both lower limbs frequently or do venous gymnastics in bed. For patients with early lower limb deep vein thrombosis, they should be absolutely bedridden for 2~3 weeks regardless of conservative thrombolysis or surgical removal to prevent thrombus dislodgement. Patients with right lower extremity onset or those with pulmonary embolism symptoms (chest tightness, shortness of breath, coughing, coughing up blood) should actively undergo life-saving inferior vena cava filter placement to prevent sudden dislodgement of the fatal embolus to the heart and pulmonary arteries leading to death from respiratory failure. Patients who have just reached clinical cure should pay attention to gradually increase the amount of activity, do not forget to wear venous drive stockings when getting out of bed, and insist on doing venous gymnastics and medication to consolidate the effect of treatment. In the later stage, if the lower extremity is complicated by stagnant dermatitis, pigmentation and ulceration (old rotten leg), the patient should actively go to the vascular surgery specialist for later comprehensive treatment.