Children with bad breath need to be treated according to the cause of the disease, if caused by bad eating habits, should adjust the diet; if caused by poor oral hygiene, periodontitis, caries, etc., it is recommended to pay attention to oral hygiene and timely consultation with the stomatology department. 1. Bad dietary habits: If children have bad dietary habits, picky eaters, easy to lead to the body’s intake of micronutrients is not enough, triggering mouth ulcers, resulting in bad breath. Therefore, attention should be paid to dietary adjustments, not picky eating and partiality. 2. Poor oral hygiene or oral disease: If children usually do not pay attention to oral hygiene, may cause periodontitis, gingivitis, dental caries and other oral diseases, resulting in bad breath. Therefore, we should pay attention to oral hygiene, brush teeth every morning and evening, rinse mouth after meals. At the same time, you should go to the dentist to take targeted treatment. 3. Indigestion: If some children have irregular diet and love to eat junk food, it will increase the burden on the stomach and intestines and cause indigestion, leading to bad breath. It is recommended to use probiotics and other drugs under the guidance of the doctor to regulate the stomach and intestines, such as Bacillus subtilis bacillus granules. Parents should help children to develop good dietary and oral hygiene habits in general, and should seek medical treatment in time if any of the above related diseases occur.