The chance of gastric ulcer becoming gastric cancer is less than 1%, a few gastric ulcers can become cancerous, and duodenal ulcers usually do not. Cancer of gastric ulcer mainly occurs at the edge of the ulcer. For long-term chronic gastric ulcers, those aged 45 years or older, and those with stubborn ulcers, cancer may occur from the edge of the ulcer. The evolution process is inflammation and erosion of the ulcer margin, mucosal atrophy with intestinal hyperplasia, further development to moderate to severe atypical hyperplasia, heterogeneous hyperplasia, and finally to gastric cancer. Therefore, it is recommended that patients who clearly have gastric ulcer need to actively cooperate with treatment under the guidance of gastroenterologists by giving PPI-like acid suppression, bismuth to protect gastric mucosa, and rehabilitation new liquid to promote ulcer repair treatment. At the same time, a carbon 13 or carbon 14 breath test should be perfected to detect the presence of H. pylori infection. If HP infection is present, formal H. pylori eradication treatment with quadruple therapy will also be given. After the treatment is completed, the electrogastroscopy will also be reviewed regularly until the ulcer is completely healed.