Gastroscopy is an important means of examining gastric, esophageal and duodenal lesions, as well as an important means of cancer examination and early cancer screening. Gastroscopy can directly observe the mucosal surface and make preliminary determination of benign or malignant tumor, but it cannot confirm the diagnosis, because the gold standard of benign or malignant tumor is pathology. Gastroscopy can biopsy the tumor to take pathology, and further confirm the diagnosis according to the pathological results. Simply put, we cannot say a person is a bad person just because he looks like a bad person, but we should take further evidence. Benign and malignant tumors have their own performance and characteristics. The surface of benign tumors is smoother and softer. Malignant tumors are hard and brittle, bleed easily when touched, and are malignant lesions that grow like cauliflower patterns.