At present, the cure rate of stomach cancer has been greatly improved compared with before. If stomach cancer is detected at early stage, the survival rate of five years of surgical treatment can reach 90%-95%, while the cure rate of one or two stages of stomach cancer is 40%-50%. Therefore, to achieve early diagnosis, we should pay attention to the following, pay attention to abnormality, regular gastroscopy and upper gastrointestinal tractography. First of all, people should pay attention to some abnormal signals of their own body, such as those who did not have stomach pain in the past, but have stomach pain repeatedly recently, or although they had stomach pain in the past. However, the nature, intensity and regularity of the pain have changed recently, longer loss of appetite, fullness and discomfort or hidden pain in the upper abdomen, unexplained weight loss, unexplained black stools and so on. Meanwhile, it is especially important to note that the peak age of gastric cancer is 40-60 years old, especially those who have tobacco and alcohol habit, unclean diet or chronic gastric diseases, such as chronic atrophic gastritis, gastric ulcer, gastric polyp, gastric resection of large part of the stomach, stump stomach, black warty gastritis, which are often known as precancerous lesions. People with high risk of gastric cancer should have gastroscopy every 6-12 months. Gastroscopy can not only directly see the lesions, but most importantly, it can obtain pathological diagnosis through biopsy. Upper gastrointestinal imaging can find out localized mucosal lesions and the extent of lesions.