Objective We tried to explore the optimal dose of esketamine combined sevoflurane for the daytime pediatric circumcision. Methods According to the random number table， children who underwent daytime circumcision were randomly divided into Group A （0.5 mL/kg esketamine）， Group B （0.75 mL/kgesketamine）， and Group C （1mL/kg esketamine） with 30 cases in each group. Each group were induced with sevoflurane inhalation anesthesia by mask and given a single intravenous dose of the corresponding esketamine after the eyelash reflex disappeared. The occurrence of intraoperative movement and esketamine bolus times was recorded. Heart rate （HR）， mean arterial pressure （MAP）， pulse oxygen saturation （SpO₂） and respiratory rate （RR） were monitored at the time of entry （T₀）， the beginning of surgery （T₁）， intraoperative ligation （T₂） and the end of surgery （T₃）. The times of opening eyes and talking after surgery were also recorded. Modified Alertness/Sedation Score （MOAA/S score） at 15 min， 30 min and 60 min after surgery， the Eastern Ontario Children's Hospital Pain Score （CHEOPS score）， Bieri Modified Facial expression score and verbal rating scale （VRS） score at the time of awakening， 2 h and 6 h after surgery were all recorded. Moreover， intraoperative and postoperative adverse reactions （respiratory depression， laryngeal spasm， agitation， nausea and vomiting， dizziness and diplopia ect.） were all marked. Results The incidence of intraoperative body movement andesketamine bolus times in Group B and C were all less than that in Group A （P < 0.05）. The time of opening eyes and talking in Group A and Group B were shorter than those in Group C （P < 0.05）. There was no significant difference in intraoperative vital signs， postoperative alertness score and pain score among the 3 groups （P < 0.05）. There was no significant difference in the incidence of adverse reactions among the 3 groups （P < 0.05）. Conclusion A does of 0.75 mg/kg esketamine combined with sevoflurane could effectively meet the anesthetic and analgesic needs of children's prepuce operation and shorten postoperative recovery time. It is the optimal dose and deserving promotion in daytime pediatric circumcision.