Gastroscopy is a means of postoperative review of gastric cancer. People often say that pre-operative gastroscopy and post-operative gastroscopy must be tested regularly, and gastroscopy is so uncomfortable, can we not do it? Gastroscopy does cause certain discomfort to human body, but the main discomfort is the patient’s own psychological influence and the degree of cooperation, just like the student’s examination, the tension in front is more obvious than the examination process. So why is it necessary to check the gastroscopy? Pre-operative gastroscopy can identify the problem and take a certain amount of specimens for laboratory tests to clarify which disease it is? Benign? Malignant? For a few patients with atypical suspected problems, one gastroscopy may fail to detect the lesion, but another one may detect the lesion in a short period of time, for example, leather stomach, or even 2-3 times repeatedly to detect the lesion. A repeat gastroscopy after radical gastric cancer surgery is a review sign to check whether there is anastomosis. Gastroscopy is generally recommended within 1 year after surgery. If gastroscopy is performed in parallel with pathological biopsy if high-grade atypical hyperplasia or evidence of gastric cancer recurrence is found, it needs to be reviewed within 1 year. Patients are recommended to undergo gastroscopy once a year. This determines the later treatment plan, whether treatment is needed or just continue to follow up and observe. Therefore, although gastroscopy is more unpleasant than ultrasound, CT and other examinations, it is still essential to follow the doctor’s advice and for your own health.