The treatment effect of gastric cancer is related to the early or late onset of gastric cancer, the type of pathology, the thoroughness of radical surgery and the comprehensive measures. Early gastric cancer has the best treatment effect. The stomach wall is divided into three layers: mucosa, muscular layer and plasma layer. Early stage gastric cancer refers to gastric cancer with cancerous tissue limited to mucosa (or submucosa layer), regardless of the size of the lesion or the presence of lymph node metastasis. Most of the early gastric cancers occur in the middle and lower part of the stomach, and the cardia is rare; overall, highly differentiated adenocarcinoma accounts for 70% and low differentiated adenocarcinoma accounts for 30%. The prognosis of early gastric cancer is related to the depth of infiltration. Intramucosal cancer rarely metastasizes to the perigastric lymph nodes, and the 5-year survival rate is close to 100%; when the cancer invades the submucosa, lymph node metastasis occurs in about 15% to 20%: the average 5-year survival rate is 82% to 95%. Because early gastric cancer has no specific symptoms, the patient’s consultation rate is low, and there is a lack of effective and convenient screening means, the proportion of early gastric cancer in hospitalized patients with gastric cancer in China is less than 15% at present. In order to improve the diagnosis rate of early gastric cancer and detect gastric cancer at an early stage, people with family members who have a history of gastric cancer or a history of previous gastric diseases should have regular checkups. Those who have upper gastrointestinal symptoms without biliary tract disease over 40 years old; those who have chronic blood loss in the gastrointestinal tract for unknown reasons; those who have significant weight loss and loss of appetite in a short period of time should have stomach-related examinations. The recommended method is fiberoptic gastroscopy plus biopsy, which is no longer difficult to diagnose gastric cancer. Electronic gastroscopy can directly observe the location and scope of gastric mucosal lesions and obtain lesion tissues for pathological examination, which is the most effective method to diagnose gastric cancer.