Gastroscopy without biopsy can detect gastric cancer, but not confirm the diagnosis. Gastroscopy is also an important means to screen and diagnose early gastric cancer, which can visualize the specific condition of gastric mucosa and timely detect tumors, ulcers and other problems, and thus can also make preliminary diagnosis on the nature of the tumor from the shape and form of the tumor, which is also capable of detecting gastric cancer, but not confirming the diagnosis. After highly suspicious lesions are found by gastroscopy, it is necessary to take tissues for pathological examination under the guidance of gastroscope in order to diagnose whether it is gastric cancer or not. Surgery is the first choice after diagnosis, while patients who cannot undergo surgery need to undergo radiotherapy and chemotherapy according to their conditions.