The baby is two and a half years old and still drooling, mostly due to digestive system diseases, oral infections and congenital diseases and so on. 1. Digestive system diseases, when there is a gastrointestinal infection, irregular diet, stomach cold and so on, there will be acid reflux and drooling. 2. Oral infections, if the child’s mouth is not clean or due to infections such as gingivitis, mouth ulcers, pharyngitis and other diseases, there will also be this performance. 3. congenital diseases, if the baby has cerebral palsy, brain dysplasia, 21 – trisomy syndrome and other congenital diseases, will also appear drooling. Baby two and a half years old still drooling, there may be other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.