Objective: To study the sedative efficacy and safety of nitrous oxide (N2O ) inhalation combined with oral midazolam in children with impacted supernumerary teeth for extraction under sedation and to provide a reference for the selection of anesthetic methods for children undergoing impacted teeth extraction. Methods : Sixty patients aged 5-10 years with maxillary impacted supernumerary teeth were randomly divided into three groups, with 20 in each group, as follows: the N2O group: N2O inhalation sedation before the operation; the midazolam group: oral midazolam sedation before the operation; the combination group: N2O inhalation combined with oral midazolam sedation before the operation. Sedation was performed before extraction under local anesthesia. The Ramsay sedation effect, Houpt behavioral score and incidence of adverse reactions were evaluated after the operation. Results: The Ramsay sedation scale score was significantly higher in the combination group (2.75 ± 0.55) than in the N2O group (2.30 ± 0.47) and the midazolam group (2.40 ± 0.50) (P ＜0.05). Similarly, the Houpt behavioral rating scale score was significantly higher in the combination group (5.25 ± 0.64) than in the N2O group (4.70 ± 0.73) and the midazolam group (4.80 ± 0.69) (P ＜0.05). The adverse reaction rate was lower in the combination group (5%) than in the N2O group (10%) and the midazolam group (10%), but the difference was not significant (χ2=0.436, p=0.804). Conclusion N2O inhalation combined with oral midazolam sedation in the extraction of impacted supernumerary teeth in children can significantly improve the sedative and therapeutic efficacy and is a safe and effective sedation method.