Blood transfusion is commonly used in clinical work to rescue patients with acute and critical traumatic blood loss and patients undergoing major surgery, and it is also a common measure to treat and correct chronic anemic diseases. Nowadays, hospital blood transfusion is distributed by the central blood station, and there is no problem with blood safety. The blood collection in the central blood station has a strict experience of procedures and tests, and there is no problem of blood carrying poison or bacteria. Safety is guaranteed. There are more than twenty kinds of diseases that can be infected by blood transfusion, but the most serious ones are common in clinical practice: one is viral hepatitis B, viral hepatitis C. The other is AIDS. The second is AIDS. The third is syphilis.