Gastrointestinal endoscopy is the most direct and highest diagnostic value routine examination of gastrointestinal system diseases, which has an irreplaceable role in the diagnosis and differential diagnosis of chronic gastritis, gastric ulcer, gastric polyp, gastric cancer, colitis, intestinal cancer and other gastrointestinal diseases. In clinical practice, this examination is necessary for many diseases, because the stimulation of local (such as throat, gastrointestinal cavity) and the physiological reaction of the body can bring discomfort and even pain to the patient, so most patients are afraid of it, and 5% of patients miss the disease because of not doing the examination. With the persuasion of doctors, only 50% of the patients do the examination, and a small number of them are unable to tolerate it, which affects the diagnosis and treatment effect and interrupts the operation, and even a very small number of patients induce stroke, arrhythmia, myocardial infarction, gastrointestinal perforation, aspiration pneumonia, etc. due to excessive tension, fear or inability to cooperate. It is the common pursuit of all gastroenterologists to eliminate the patient’s fear and the pain and discomfort during gastroscopy. For this reason, in recent years, painless gastroscopy has been widely carried out in major hospitals at home and abroad, and more than 50% of patients in large hospitals in Shanghai choose painless gastroscopy. The superiority of painless gastroscopy is reflected in the following three aspects: firstly, the patient is not conscious and painful during the operation, and most of them also have a comfortable feeling, which excludes the discomfort and painful experience brought by the gastroscopy operation; secondly, it enables the operating physician to complete the corresponding examination and treatment calmly, carefully and thoroughly, which can In addition, it may help to reduce complications such as cardiovascular accidents, stomach cramps, bleeding, perforation, etc. caused by nervousness, fear and non-cooperation. Patients who undergo painless gastroscopy often begin to wake up within 5 minutes of the end of the examination, and the majority can leave the hospital safely after 20 minutes, accompanied by their families.