The clinical symptoms of precancerous stage of gastric cancer are not very obvious, which may only show mild abdominal distention, epigastric pain, dyspepsia, nausea, vomiting, etc. It is not typical and is easy to be confused with digestive system diseases such as gastritis and gastric ulcer. With the progression of the disease, the patient may have clinical symptoms such as upper abdominal mass, persistent abdominal pain, malnutrition, and emaciation. It is necessary for the patient to seek medical examination as soon as possible. Gastroscopy, especially pathological examination, can be used to diagnose gastric cancer disease and early diagnosis and treatment.