Lower extremity deep vein thrombosis is common in patients with surgery, trauma, long-term bed rest, tumor of hypercoagulable state, sudden onset of lower extremity swelling with pain, swelling is finger trapped, aggravated when standing, relieved after rest, with local skin temperature increase, is a serious impact on the quality of life, the incidence is high, the acute phase may be complicated by pulmonary embolism, the mortality rate is extremely high, the late legacy of deep vein thrombosis syndrome, seriously affect the life The disease has a high incidence and may be complicated by pulmonary embolism in the acute phase with a high mortality rate and deep vein thrombosis syndrome in the later stages, which can seriously affect the quality of life. The disease is currently characterized by a high rate of misdiagnosis, untimely treatment in the acute phase, and irregular treatment in the chronic phase.