Universal recipient blood type, usually means AB blood type, because AB blood type people can receive a small amount of blood of other blood types in emergency situations, but only if there is no blood of the same blood type available in emergency situations, in order to save the patient’s life, a small amount of blood of other blood types can be used, but if there is blood of the same blood type, the first thing is still to apply the blood of the same blood type, which is also the clinical The reason for the principle of transfusion of homozygous blood. In the past, people referred to AB blood type as the universal recipient, and at the same time referred to O blood type as the universal transfusion, but this was a measure taken only when there was no alternative. Today, blood transfusion is based on the principle of homotypic blood transfusion, and heterotypic blood is rarely transfused.