Remimazolam besylate (RB), as a new benzodiazepine sedative agent, has been approved in clinical anesthesia with prominent characteristics of short onset/offset, less depression for cardiovascular or respiratory function and specific antagonist. Some studies have confirmed the comparable anesthesia efficacy of remimazolam for outpatient digestive endoscopy, fiberoptic bronchoscopy, facial plastic and orthopedic surgery as propofol. Currently, the evidence on its application in cardiac anesthesia is insufficient. Our study aims to evaluate the efficacy of remimazolam besylate and propofol and provide an ideal anesthetic agent to achieve the goal of early recovery after cardiac surgery.