Gastric cancer is a common malignant tumor worldwide, and its clinical symptoms are usually indistinguishable from benign diseases; therefore, most gastric cancer patients are in the middle to late (progressive) stage once detected. The 5-year survival rate of surgical treatment effect of early gastric cancer can reach over 90%, so early diagnosis and treatment are very important. At present, the detection rate of early gastric cancer in Japan can reach 50-60% through dual gas-barium imaging and gastroscopy, and the rate of early gastric cancer in Korea has reached 30-40%. In China, the proportion of early gastric cancer is about 10% at present, and in a few large medical centers, it can reach about 20%. Therefore, it is very important to pay attention to early gastric cancer screening, early detection and timely treatment to improve the 5-year survival rate of gastric cancer patients. The vigilance of clinicians, the attention of patients and the experience of endoscopists and pathologists are very important to improve the detection rate of early gastric cancer at present.