Excessive blood loss will cause a decrease in blood volume in blood vessels and ischemia in tissues and organs. If the rapid blood loss exceeds 20% of the total blood volume in the body, which is about 1000 ml, a person will suffer from hemorrhagic shock and become life-threatening. The treatment of excessive blood loss mainly includes replenishment of blood volume and treatment of the primary disease causing excessive blood loss, and control of bleeding. Replenishing blood volume and treating the primary disease and controlling bleeding should be carried out simultaneously. Replenishing blood volume means quickly lancing and quickly infusing fluids, firstly, balanced salt solution and artificial colloid fluid, such as hydroxyethyl starch, and blood transfusion if the anemia is serious after bleeding. While replenishing blood volume, attention should also be paid to the prevention and control of acidosis and electrolyte disorders. It is not enough to replenish the blood volume, so it is also necessary to treat the original disease, control the bleeding, and most importantly, to find the cause of bleeding and identify the place of bleeding, which often requires emergency surgical treatment to stop the bleeding.