Baby’s bad breath and halitosis should be treated differently according to different causes, which may be caused by oral diseases or throat diseases or stomach diseases. It is recommended to consult a doctor for diagnosis and targeted treatment. 1. Periodontitis: the bacteria in the mouth will continue to grow, will make the mouth odor, can be coated with antibiotic ointment such as metronidazole ointment under the guidance of a doctor, if accompanied by Candida albicans infection, can be coated with clotrimazole cream or mycobacteria under the guidance of a doctor. 2. pharyngitis: localized inflammatory exudation occurs in the affected area of the throat. When the baby exhales from the mouth, he/she may smell bad odor, he/she can take Roxithromycin orally or gargle with saline under the doctor’s guidance. 3. Gastroesophageal reflux: Gastroesophageal reflux disease can cause acid reflux in the stomach, which can cause bad breath in babies. You can take oral Bacillus subtilis bacillus granules and Lactobacillus acidophilus to regulate the intestinal flora under doctor’s guidance, and take pepsin to help digestion. It is recommended to take the baby to the hospital in time to find out the cause of the disease, symptomatic treatment. Pay attention to moderate consumption of fresh vegetables and fruits, as well as fresh meat, eggs and milk, etc.; to maintain oral environmental hygiene parents should apply the correct way of brushing to help the baby brush their teeth, try to avoid oral foreign body residues.