Clinically, if patients need blood transfusion, different blood products will be used, there are 4 kinds of blood products routinely used, red blood cells, plasma, cold precipitation, platelets, routinely usually transfuse 1 or 2 kinds, but also at the same time 4 kinds of transfusion, mainly special rescue patients, if at the same time the need for transfusion of 4 different blood products, there is no technical specifications and guidelines to stipulate the order of transfusion. At present, it is believed that the order of transfusion is decided in accordance with the inactivation state and time duration of the blood products leaving the preservation environment conditions of the transfusion department, and it is generally stipulated that platelets should be transfused first, followed by cold precipitation, plasma, and finally red blood cells. However, in the case of massive bleeding, it is not necessary to follow the above order, and red blood cells must be transfused first, because the blood pressure drops sharply and the blood volume drops sharply, and red blood cells must be transfused first to save the patient, so blood transfusion should be decided according to the individual differences, and the order of transfusion of different blood products should be judged according to the state of the disease at that time.