Gastric ulcer 4×5 cm belongs to a special type of gastric ulcer called giant ulcer, which is more serious when complicated by perforation and bleeding. Giant ulcers are ulcers with a diameter greater than 2cm, commonly seen in elderly patients and long-term use of non-steroidal anti-inflammatory drugs, is an inflammatory defect in the gastric mucosa, related to the secretion of gastric acid from the gastric juice and the role of digestion, the lesion can reach the muscularis propria or a deeper level, the main symptom is the long-term cyclic episodes of epigastric pain. Common complications include bleeding, perforation, pyloric obstruction, and cancer. Gastric ulcer patients should change their living habits, eat a light diet, quit smoking, quit drinking, drink less strong tea and coffee, avoid staying up all night, and try to stop using medicines that are irritating to the stomach. Those with gastric ulcers 4×5 cm are advised to take medication regularly under the guidance of a doctor to reduce the occurrence of complications.