Children’s breath odor may be caused by physiological factors, at this time can improve the life, dietary habits; may also be pathological factors, such as periodontitis, indigestion, etc., can be scaling, drug treatment. I. Physiological causes: short-term bad breath often occurs in the morning, and can be eliminated after brushing teeth. First of all, consider children’s bad breath caused by improper brushing, parents are advised to teach children the correct way of brushing, and develop the habit of rinsing the mouth after meals; it can also be caused by garlic, onion, etc. after metabolism to produce some foul-smelling substances through the lungs and exhaled from the oral cavity. There is no special treatment at this time. II. Pathological factors 1. Periodontitis: chronic inflammation of periodontal tissues caused by plaque biofilm. Bad breath can occur, accompanied by tartar accumulation, loose teeth, etc. At this time, you can improve the bad breath phenomenon through careful brushing, scaling and other ways. 2. Dyspepsia: bad breath can also occur, accompanied by acid reflux, nausea, vomiting, anorexia, heartburn and other symptoms, can be improved by improving the child’s lifestyle, adjusting the dietary structure and habits, and oral omeprazole, magnesium alumina carbonate and so on to alleviate halitosis in children. All of the above medications should be used under the guidance of a doctor and avoid self-medication. There are many other causes of halitosis in children, and it is recommended to seek medical attention in a timely manner to have the child evaluated by a specialist, complete the relevant examinations, and provide targeted treatment or therapy.