The reasons why children brush their teeth and vomit are as follows: First, the use of too much toothpaste will produce rich foam, if not timely application of water rinse, rinse, will stimulate the mucous membrane of the throat, resulting in dry vomiting phenomenon. Second, the head of the toothbrush is too large, or when the toothbrush is too extended to the back of the mouth, it can cause the pharyngeal reflex, nausea, vomiting, etc. Third, if the child’s soft and hard palate is cleft and the oral cavity is penetrated with the nasal cavity, a large amount of liquid will enter the nasal cavity when brushing, causing a larger reaction. Fourth, when the child often has a cold or fever, the soft palate and throat are obviously swollen, producing a foreign body sensation and even forming chronic pharyngitis, and the stimulation of bristles and foam when brushing teeth can easily stimulate symptoms such as dry vomiting.