The preparations to be made before gastroscopy include keeping an empty stomach, checking the electrocardiogram, doing routine laboratory tests and taking anesthetics. 1. Maintaining an empty stomach: It is necessary to maintain an empty stomach for at least 6 to 8 hours before performing a gastroscopy. Generally speaking, you should not eat or drink after 10 p.m. on the night before the examination, which will lead to more food remaining in the stomach. Stimulation of the stomach by the gastric tube during the gastroscopy may cause vomiting, resulting in inaccurate test results. 2. Electrocardiogram: Electrocardiogram can understand the state of the heart and determine whether the blood supply, conduction system and morphology of the heart are in a normal state. If the heart is abnormal, the patient usually can not undergo gastroscopy, which will induce a heart attack and symptoms such as dyspnea and angina pectoris will occur. 3. Routine laboratory tests: Routine laboratory tests are mainly to determine whether the patient suffers from hepatitis B, AIDS and other infectious diseases, and to decide the order of gastroscopy and the use of instruments to prevent cross-infection. 4. Taking anesthetics: Because gastroscopy is very difficult to do, especially the pharynx is narrow, the gastric tube is not easy to insert, which will bring pain to the patient doing gastroscopy. Therefore, you can follow the doctor’s instructions to take appropriate endoscopic lubricants such as bupivacaine hydrochloride and dacronine gel paste, anesthetics, to reduce the patient’s pain. Specific preparations and precautions can be carried out as prescribed by the doctor.