Quadruple therapy is a common treatment for Helicobacter pylori infection, i.e. 1 proton pump inhibitor + 2 antibiotics + 1 bismuth agent, such as omeprazole, amoxicillin, clarithromycin, and bismuth potassium citrate. The specific dosages are as follows: 1. amoxicillin 1g , 2 times/day; clarithromycin 0.5g, 2 times/day, half an hour after meal orally. Omeprazole 20mg, 2 times/day; bismuth potassium citrate 220mg, 2 times/day, taken orally half an hour before meals. 2. Amoxicillin 1g , 2 times / day; levofloxacin 0.2g, 2 times / day, half an hour after meals orally. Lansoprazole 30mg, 2 times/day; bismuth potassium citrate 220mg, 2 times/day, half an hour before meals orally. Suffering from Helicobacter pylori infection, it is recommended to go to the gastroenterology department of regular hospitals, and use medication under the guidance of doctors.