Weakly positive PHE in newborns often suggests congenital phenylketonuria, which is generally incurable and can be alleviated mainly through dietary nutrition and medication, and the earlier the intervention, the better the therapeutic effect can be achieved. 1. Dietary treatment: for newborns with phenylketonuria, the most critical treatment is to strictly control the diet and reduce the intake of phenylpropionic acid, the earlier the treatment, the better the prognosis. Infants can be fed special low-phenylalanine formula, and some starchy, vegetable-based low-protein supplements such as cornstarch can be added. 2. Medication: Due to the large individual differences, appropriate medication should be chosen under the guidance of a doctor. Tetrahydrobiopterin is the main drug for the treatment of phenylketonuria, and the therapeutic effect can be achieved by supplementing tetrahydrobiopterin. Allopurinol tablets can effectively inhibit uric acid, to a certain extent, effective relief of phenylketonuria. When a newborn baby becomes unwell, he should go to the hospital immediately. All of the above medications should be used under professional medical supervision.