1, the patient should be lying on the left side, legs flexed, loosen the collar and trouser pocket, head slightly tilted back, so that the pharynx and esophagus become a straight line; 2, the doctor will lay a sterile towel or towel next to the patient’s mouth, and then place a curved tray on the towel to receive saliva or vomit, the patient needs to follow the doctor’s instructions to bite down on the dental pad; 3, the doctor holds the gastroscope operating site, insert the gastroscope through the mouth into the pharynx under direct vision, slowly along the back of the tongue, pharynx Insert the gastroscope into the esophagus under direct vision, slowly along the back of the tongue and the wall of the throat, and inject an appropriate amount of air. The patient needs to breathe deeply through the nose with swallowing action to reduce nausea and facilitate the dismantling of the scope. 4. The patient can sit up and spit out saliva after withdrawing the scope.