With the further development and improvement of gastroscopy technology in gastroenterology, the clinical significance of gastrointestinal diseases has become more and more prominent and its clinical application has become more and more widespread, while at the same time, patients’ demand for the comfort of gastroscopy has become stronger and stronger. Therefore, painless gastroscopy has emerged. What are its indications, contraindications and precautions? This article briefly discusses them as follows. Indications: (other than the same as ordinary gastroscopy) 1, painful operations and treatments: esophageal dilation, endoesophageal stent placement, ERCP, percutaneous gastrostomy, pancreatic port polyp removal; 2, those who have a poor impression of endoscopy; 3, those who are heavily nervous or tense, and those who are strongly requested by patients. Contraindications: (other than the same as general gastroscopy) 1, age > 70 years; 2, serious pulmonary disorders: COPD, sleep apnea syndrome, oxygen saturation <90% in natural state, hypotension (<80/50mmHg), allergy to anesthetics, pregnancy, myasthenia gravis. Precautions and complications: (other than the same as general gastroscopy) 1. preoperative conversation, sign the anesthesia informed consent form, understand the benefits and potential risks of the examination; 2. preoperative preparation must be adequate, absolutely no water before the examination, because systemic intravenous anesthesia may cause aspiration, causing aspiration pneumonia; 3. preoperative vital signs check; 4. anesthesia accidents: respiratory depression, myocardial ischemia, arrhythmia, hypotension, hypertension, hypertension, drug allergy. hypotension, hypertension, drug allergy; 5. Risk factors for increased complications: too old or too young, vital organ insufficiency, alcohol or drug addiction, morbid obesity, severe lung disease, difficult esophageal insertion, emergency gastroscopy; 6. Patients over 60 years old need to provide the results of ECG examination in the last 2 weeks.