The causes of gastric ulcer mainly include Helicobacter pylori infection, excessive use of non-steroidal anti-inflammatory drugs, digestive effects of gastric acid and pepsin, and abnormal gastroduodenal motility. 1. Helicobacter pylori infection can cause gastric mucosal inflammation and weaken the mucosal barrier function. 2. Non-steroidal anti-inflammatory drugs, non-steroidal anti-inflammatory drugs can damage the mucosal defense mechanism and repair function, when long-term use of such drugs, the gastric mucosal damage can not be repaired in a timely manner, and over time the formation of gastric ulcer. 3. The digestive effect of gastric acid and pepsin, gastric ulcer occurs when gastric mucosa is damaged due to excessive secretion of gastric acid. 4. Abnormalities in gastroduodenal motility, weakened gastric emptying ability makes the gastric mucosa more susceptible to damage by gastric acid and pepsin, and other factors such as smoking, hereditary factors, and acute stress situations. Gastric ulcers should be treated immediately, and the cause should be clarified under the guidance of professional physicians.