Immediate family members with the same blood type can transfuse blood from each other, but blood transfusions between immediate family members with different blood types are not allowed. Commonly used blood components for clinical transfusion are suspended red blood cells, washed red blood cells, single platelets, plasma and cold precipitate. Clinical blood transfusion can only be carried out if the blood components of the same blood group are transfused and if there is no agglutination reaction after cross-matching before transfusion. Therefore, as long as the blood groups between immediate family members are the same and there is no agglutination reaction in cross-matching, they can transfuse each other’s blood. Clinical blood transfusion needs to strictly grasp the indications for blood transfusion to avoid wasting blood resources, and transfusion reactions (chills, shivering, fever, rash, hemolysis, etc.) may occur during the transfusion process, which may be life-threatening in severe cases. Therefore, the physician should choose the appropriate blood components for transfusion according to the patient’s condition and closely observe the patient to see if any transfusion reaction occurs.