Lower extremity venous thrombosis is a common peripheral vascular disease. Venous valve insufficiency and pulmonary embolism caused by venous thrombosis of lower limbs are very dangerous to the labor force and life safety of patients. This disease has been paid attention to in clinic. /kloc-VIRCHOW, a famous physician in the 0 ~ (th) century, proposed that the three major factors of venous thrombosis are blood stagnation, venous wall injury and hypercoagulability. Thrombosis of left lower limb is much higher than that of right lower limb, especially primary iliofemoral vein thrombosis. Sometimes venous thrombosis of lower limbs can also extend to inferior vena cava and even block renal vein, causing renal failure and threatening life.