Baby spit up like water may be physiological phenomenon, may also be indigestion and other reasons. 1. physiological phenomenon: pediatric stomach capacity is small, and the stomach is in a horizontal state, the cardia sphincter relaxation, eating too much or eating too fast to cause the milk from the stomach reflux out of the reflux of milk mixed with digestive juices will be like water. 2. indigestion: pediatric gastrointestinal delicate, easy to indigestion, indigestion caused by part of the milk fat precipitation in the stomach, there will be spit watery milk, usually accompanied by bloating, diarrhea, crying and other symptoms. The baby spit up like water may also have other reasons, it is recommended to go to the hospital, improve the examination to clarify the cause of the disease, give targeted treatment or standardized treatment.