Gastric ulcer is a common digestive tract disease, which is prone to recurrence. Patients with gastric ulcer may be converted to cancer, and those with gastric ulcer accompanied by chronic atrophic gastritis are at high risk of gastric cancer. Cancer in gastric ulcer patients usually occurs due to recurrent ulcers, inflammation and other factors that repeatedly stimulate the mucosal epithelium at the edge of the ulcer for a long time, resulting in repeated destruction and repair of the mucosal epithelium, which gradually develops into gastric cancer. The transformation of ulcer patients into gastric cancer occurs around the age of 40, and there are relatively more people who have gastric ulcer transformed into gastric cancer. Usually, patients with gastric ulcers develop cancer on the side of the gastric lesser curvature, and if the ulcer margin is not neat and the ulcer base is not flat, the ulcer is located at the greater curvature of the stomach. Therefore, patients with gastric ulcer are recommended to actively treat the ulcer and have regular gastroscopy to prevent cancer from occurring. It is also necessary to pay attention to the prevention of ulcers from becoming cancerous in daily life and to correct bad dietary habits. When patients with gastric ulcer have frequent pain, black stool, unexplained low fever, weight loss, etc., they should go to the hospital for examination in time to avoid delaying the disease.