ABO hemolytic jaundice is an immune hemolytic disease caused by blood group antigen-antibody reaction between mother and baby due to blood group incompatibility. It mostly occurs in babies whose mothers are blood type O and fathers are not blood type O. Progressive severe jaundice occurs 2~3 days after birth, and can also cause edema, hepatosplenomegaly and anemia. When the baby’s mother has blood type O and the baby’s blood type is A or B, the blood type antigen A or B on the fetal red blood cells enters the mother’s blood through the placenta and produces blood type antibody, which then returns to the fetus through the placenta and combines with the blood type antigen A or B on the fetal red blood cells, causing fetal red blood cells to agglutinate and dissolve and hemolysis, and delayed treatment can lead to kernel jaundice. Once ABO hemolytic disease is diagnosed, it is important to be hospitalized in time to avoid missing the effective treatment.