Pre-stage gastric cancer, also known as early gastric cancer, refers to lesions involving only the mucosa or submucosa, regardless of the size of the lesions and the presence or absence of lymph node metastasis. Early gastric cancer can be divided into 3 types according to its morphology: Type I elevated row, where the cancer lesion protrudes into the stomach lumen. Type II superficial type, the cancer foci are relatively flat, without obvious elevation and depression. Type III depressed type, which is a deeper ulcer. Patients with early gastric cancer have no obvious symptoms, sometimes they may experience non-specific symptoms such as upper abdominal discomfort, fullness after eating, nausea and indigestion. Surgery is the main treatment for gastric cancer and the only way to cure gastric cancer. Therefore, early stage of gastric cancer has relatively good prognosis and should be treated by surgery as early as possible.