Large vessel injuries are extremely life-threatening. Arteriovenous vessels in various parts of the body are subject to sharp-edged stab wounds, cuts, cuts or gunshot wounds, which can cause vascular rupture, resulting in acute and massive bleeding and directly endangering life. According to statistics, the mortality rate of bleeding caused by large vessel injury is 54.1%, and the physiological response of the body to acute blood loss in different parts of the body varies greatly. The closer the blood loss to the heart, the worse the tolerance of the body. When the thoracic and abdominal arteries are injured, the blood loss is more rapid and the blood loss is greater because the pressure on this part of the blood vessels is greater than the pressure on the distal vessels. Often it is too late to rescue and quickly cause death, rupture of the thoracic and abdominal aorta, blood loss as long as it reaches one-third to one-fourth of the whole body blood volume, about 1500-2000 ml, will cause a sharp drop in blood pressure, causing heart paralysis and rapid death. On the contrary, the body shows great tolerance to blood loss away from the heart or chronic blood loss, even when the blood loss is more than half the volume still does not cause death. When bleeding from ruptured small arteries in the extremities or ruptured body veins, the body will naturally adapt and show a high tolerance to blood loss because the pressure of blood flow is relatively weak and the rate of blood loss is slow. However, when chronic blood loss exceeds 4000 ml, reaching two-thirds of the total body blood, it can also cause death. In particular, cervical vascular and External iliac artery injury is a highly fatal injury. Statistically the mortality rate caused by it can be as high as 24%-60%, early onset is often accompanied by severe shock, and because it is often accompanied by injury to the adjacent system, it is easy to cause death by late onset sepsis. These factors often make it difficult for surgeons to deal with. Diagnosis: (1) Rapid and effective control of hemorrhage. The most effective method to stop bleeding in the field emergency is gauze tamponade compression to stop bleeding. Specialists compressing the injury were transferred to our hospital. (2) Take a detailed medical history. Understand the cause of the injury to estimate its possible involvement of blood vessels, tissues and organs. If the wound bleeding at the time of injury is jet bright red or accompanied by pallor, shock and other phenomena, then the diagnosis of arterial injury can be clear. On-site first aid: 1, local pressure, pressure bandage. 2, ring tie hemostatic rubber band binding time can not exceed one hour. If it is a large trauma, local pressure hemostasis effect is not good, can be tied in the upper 1/3 plane of the upper arm or thigh tourniquet, the pressure must be high, higher than the human blood pressure systolic pressure 50-100mmhg to effectively stop bleeding. Caution: Do not tie the middle and lower part of the upper arm, it is easy to compress the flexural nerve and lead to nerve injury, and it is necessary to record the tourniquet time and relax it for 10-15 minutes after 1 hour.