OBJECTIVE To obser ve the efficacy and safety of rimazo lom for painless gastroscopy sedation in outpatients. METHODS Totally 84 patients who underwent painless gastroscopy were collected from the outpatient department of the Central Hospital of Enshi Tujia and Miao Autonomous Prefecture from March to June in 2021. By random number table method combined with envelope allocation concealment method ，they were randomly divided into observation group and control group ，with 42 cases in each group. The patients in the observation group were slowly injected with Sufentanil citrate injection 0.1 μg/kg+Rimazole toluenesulfonate for injection 0.2 mg/kg. Patients in the control group were slowly injected with Sufentanil citrate injection 0.1 μg/kg+ Propofol emulsion injection 2 mg/kg. Gastroscopy was performed after the patient ’s consciousness disappeared. The sedative efficiency，sedative onset time ，recovery time and the occurrence of adverse drug reaction were observed in 2 groups. The heart rate（HR），mean arterial pressure （MAP），pulse oxygen saturation （SpO2），modified observer ’s assessment of alertness/sedation （MOAA/S）score and Narcotrend score were recorded in 2 groups after entering the room （T0），after anesthesia induction （T1）， when gastroscope entered the throat （T2），at the end of gastroscope withdrawal （T3），5 min after gastroscopy （T4）. RESULTS There was no significant difference in the effective rate of sedation （100％），the incidence of respiratory depression ， nausea and vomiting between the two groups （P＞0.05）. The qq.com onset time of sedation in the observation group was longer than control group ，and the recovery time and the incidence ofhypotension，hypotension to be tre ated，injection pain and bradycardia in observation group were significantly shorter or lower than control group （P＜0.05）. At T 0，there was no significant difference in HR ，MAP，SpO2，MOAA/S score or Narcotrend score between two groups （P＞0.05）. From T 1 to T 4，the HR of control group was significantly lower than that of the same group at T 0，and significantly lower than observation group at the same time（P＜0.05）. From T 1 to T 3，the MAP of two groups were significantly lower than the same group at T 0（P＜0.05），but there were no significant differences between two groups and between T 4 and T 0（P＞0.05）. There was no significant difference in SpO 2 at different time points between two groups and HR at different time points in observation group （P＞0.05）. From T 1 to T 3，MOAA/S score and Narcotrend score of two groups were significantly lower than the same group at T 0，while the MOAA/S score and Narcotrend score at T 1 and T 3 and Narcotrend score at T 3 of observation group were significantly higher than control group at the same time （P＜0.05），and the Narcotrend score of observation group at T 2 was significantly lower than control group at the same time（P＜0.05）；at T 4，there were no significant differences in MOAA/S score and Narcotrend score between two groups （P＞ 0.05）. CONCLUSIONS Remazolam shows good sedative effect and safety for painless gastroscopy.