Gastric cancer is a malignant tumor of digestive system, which originates from gastric mucosal cells. The manifestation of early gastric cancer under gastroscopy is that the diameter of tumor is small and not easy to be observed, the gastric mucosa will be rough and uneven, and the stomach is accompanied by bleeding or even erosion. Early gastric cancer can be divided into three types: augmented gastric cancer, superficial gastric cancer and depressed gastric cancer.1. In augmented early gastric cancer, the tumor is in the gastric mucosa, and the surface is polypoid and augmented, the surface mucosa will be congested and red, and will bleed when squeezed, and some patients will have gastric bleeding and ulcers.2. Superficial early gastric cancer, i.e. gastric inflammatory gastric cancer, has symptoms of gastric mucosa erosion and granularity, and this type of gastric cancer does not have This type of gastric cancer has no obvious lesion characteristics, so it is difficult to be diagnosed in early stage. 3. Indurated type of early gastric cancer, i.e. ulcerated type, is endoscopically granular or nodular, with symptoms such as erosion, congestion and bleeding on the indurated side of the lesion, and is evolved from chronic ulcer disease.