Objective To observe the application effect of Sevoflurane inhalation by combined inhalation anesthesia induction device in reduction developmental dysplasia of the hip (DDH) in children. Methods A total of 97 children with the diagnosis of DDH were selected from the People's Liberation Army Ground Force Seventy-three Military Hospital,Chenggong Hospital affiliated to Xiamen University from January 2016 to January 2020, and divided into group G (n=49)and group D (n=48)by random number table method.The group G was inhaled Sevoflurane 2 ml once by using combined inhalation anesthesia induction device before manual reduction with the supplementary dose of Sevoflurane 2 ml once, and group D was injected Ketamine 4-5 mg/kg through deltoid muscle with the supplementary dose of 0.5 mg/kg intravenously. The mean arterial pressure (MAP), heart rate (HR), blood oxygen saturation (SpO2), sleeping latency, wakening time, and the total incidence of adverse events were collected and analyzed at pre-anesthesia (T1), pre-operation(T2), and post-operation (T3). Results There were no significant differences in MAP, HR and SpO2 between the two groups at T1 (P＞0.05). The fluctuation of MAP, HR in group G at T2 and T3 were lower than those in group D, with statistically differences (P＜0.05). There were no significant differences in SpO2 at T2 and T3 between group G and group D(P＞0.05). The fluctuation of MAP, HR in group Gg at T2 and T3 were lower than those in group Dd in children of who required manual reduction after adductor amputation,with statistically differences (P<0.05).There were no significant differences in SpO2 at T2 and T3 between group Gg and group Dd (P＞0.05). The sleep latency in group G was longer than that in group D,with statistically difference(P<0.05).The awakening time was shorter than that in group D, with statistically difference (P<0.05). The total incidence of adverse events in group G was lower than that in group D, with statistically difference (P<0.05). Conclusion Compared with traditional anesthesia applied by ketamine, the inhalation of Sevoflurane by combined inhalation anesthesia induction device during manual reduction of DDH in children were more humanization and safety, and with the advantages of stable anesthesia, rapid recovery and less incidence of adverse events. It is a safe and effective anesthesia method.