H. pylori infection can cause bad breath because H. pylori is often found in the digestive tract and can also colonize the periodontal pockets. Infection with H. pylori in the stomach may lead to indigestion, bloating, acid reflux, heartburn, etc., resulting in bad breath, which is usually not relieved by oral cleansing and can only be relieved after eradication of H. pylori. In contrast, periodontal pathogenic bacteria such as H. pylori in periodontal pockets can be controlled by systematic periodontal treatment. Treatment of halitosis caused by H. pylori, commonly used methods are as follows: 1, daily cleaning: timely dental cleaning, while paying attention to personal hygiene, keep the oral cavity clean, so as to avoid the breeding and reproduction of H. pylori in the mouth; 2, drug therapy: the use of anti-H. pylori drugs, commonly used bismuth plus proton pump inhibitors, two antibacterial drugs consisting of quadruple drug therapy. Proton pump inhibitors often choose omeprazole or rabeprazole, bismuth often choose bismuth pectin or bismuth potassium citrate, etc., antibiotics commonly used amoxicillin, clarithromycin, metronidazole, etc.. Under the guidance of doctors, digestive drugs such as dry yeast tablets, multi-enzyme tablets, lactase tablets, etc. can be consumed. Drugs that promote gastric motility, such as mosapride, can also be used to help gastric emptying and improve gastric function. H. pylori in periodontal pockets can be treated with a combination of periodontal benchmark therapy as well as with a combination of quadruple drug therapy. In addition, if bad breath is still present after complete eradication of H. pylori, it is necessary to exclude the presence of dental calculus or oral inflammation in the mouth, and patients are advised to go to the dentistry department for examination and confirmation of the diagnosis and treatment of the cause.