Sedation and analgesia techniques are widely used in endoscopic diagnosis and treatment. The main purpose is to relieve the anxiety and pain of patients and reduce the risk of complications. Esketamine has obvious advantages in the clinical application of sedative and analgesic endoscopy. For example, it has strong sedative and analgesic efficacy, slight influence on respiratory circulation with its sympathomimetic properties, rapid recovery, improved postoperative cognitive function, and fewer adverse reactions. However, due to the dose-dependent side effects of esketamine, it is necessary to pay attention to adverse reactions such as increased drainage, psychotropic symptoms, nausea and vomiting, and vertigo. This article summarizes the clinical effect of esketamine, the selection of drug dosage and the research progress of clinical application in special population during diagnosis and treatment of digestive endoscopy, respiratory endoscopy and gynecological endoscopy, in order to provide a reference for clinical research and drug guidance.