Objective To compare the effects of different administration sequences of propofol and remimazolam on patients respiration, circulation, and adverse reactions during painless gastroscopy.Methods Patients who underwent painless gastroscopy at Renmin Hospital of Wuhan University from March to June 2023 were 1 ∶ 1 randomly divided into two groups using random number table method: the Remimazolam-Propofol group (RP group) and the Propofol-Remimazolam group (PR group). After both groups of patients were administered sufentanil 0.1 ug·kg-1, patients in RP group were pre-administered remimazolam 0.15 mg·kg-1, and then followed by pump injection of propofol at an injection rate of 40 mg·kg-1·h-1; patients in PR group were pre-administered propofol 0.5 mg·kg-1, and then followed by pump injection of remimazolam at an injection rate of 3mg·kg-1·h-1. When narcotrend (NT) value 0.05). There was no significant difference between the two groups in anesthesia effect indicators such as the dosage of remimazolam and propofol, anesthesia time, awakening time, leaving hospital time, body movement cases, assisted breathing cases, and peri-examination adverse reaction indicators, such as bradycardia, hypotension, respiratory depression, hypoxemia, nausea, vomiting, dizziness and fatigue (P>0.05), but the propofol injection pain in RP group was significantly less than that in PR group (P