Baby spit up needs to be analyzed, usually babies occasionally spit up is difficult to avoid, small babies spit up itself is not a matter of concern, but spit up may cause milk inhalation into the trachea, which is a certain danger: first, must prevent spitting up, choking, do try to feed a little less at a time, and then feed a few more times. Second, relax the waist belt, or do not use the waist belt, let go of the stomach to eat, so that it is not easy to vomit. Third, try to move as little as possible after feeding and sleep on your side. Fourth, supplement vitamin D and calcium, sometimes calcium-deficient babies, crying is also easy to cause vomiting. Fifthly, keep watch at all times, once vomiting should be cared for immediately to avoid the milk being sucked back into the trachea. If the milk is really like phlegm, the vomiting may be a mixture of milk and phlegm, and at this time the baby may be accompanied by coughing, and may sometimes hear the sound of phlegm. Then consider that it may be an upper respiratory tract infection, bronchial infection, which requires targeted treatment.