Blue light irradiation is currently a safe and effective way to reduce jaundice. If jaundice still recurs after blue light irradiation, it may be caused by insufficient irradiation time or combined pathological jaundice. It is necessary to consult a doctor in time to determine the cause and treat the cause. Common causes and treatment methods 1, the irradiation time is not enough: blue light irradiation can transform the skin surface of the bilirubin, so that it is converted into light isomer, and then from the body to discharge, generally need to irradiate 3-4 days. If the irradiation time is not enough, the rate of bilirubin destruction may be greater than the rate of bilirubin excretion by blue light irradiation, resulting in repeated attacks of jaundice. It is recommended to follow medical advice for treatment to ensure sufficient irradiation time; 2. Combined pathological jaundice: the jaundice recedes and then recurs in the child, which may be combined with pathological jaundice. Yellow staining of the face, trunk, hands and feet, accompanied by anemia, fever, poor response, depression, anorexia and other symptoms. Drugs can be applied to accelerate the metabolism of bilirubin or inhibit the enterohepatic circulation of bilirubin. Liver enzyme inducers such as phenobarbital and oral probiotics can be used for treatment, and intravenous immunoglobulin can be used to block hemolysis when combined with hemolytic disease, thereby reducing the production of bilirubin. In case of recurrent blue light jaundice in newborns, parents can give the child appropriate probiotics and increase outdoor activities. If breast milk jaundice is identified and the jaundice is severe, breastfeeding should be suspended.