Children with bad breath should pay attention to timely brushing and rinsing before and after meals; it may be caused by oral diseases, indigestion and other factors. It is recommended to go to the hospital in time to do the relevant examination to clarify the cause of bad breath and give appropriate treatment. 1. Oral disease: periodontitis infection in the mouth will make the child have bad breath. It is recommended that parents should give their children a good oral cleaning, pay attention to brushing teeth before and after meals, rinse mouth, so as not to let the bacteria grow in large quantities. 2. indigestion: generally children eat a lot of food, in the stomach can not be digested, has been in the intestinal tract retention, fermentation will appear putrid smell, which leads to bad breath, accompanied by nausea, vomiting, heartburn and other symptoms, it is recommended that under the guidance of the doctor, oral probiotics (such as bacillus subtilis bacillus granules) and other medications, should pay attention to local oral hygiene. Children’s bad breath may also be related to other factors, it is recommended to consult a doctor in order to clarify the cause of the disease and standardize the treatment.