Objective:To evaluate the efficacy of esketamine-based anesthesia in lumbar spine surgery.Methods:Ninety-four patients of both sexes, aged 18-64 yr, with body mass index of 18.5-29.9 kg/m 2, of American Society of Anesthesiologists Physical Status classification ⅠorⅡ, scheduled for elective lumbar posterior decompression bone grafting fusion internal fixation under general anesthesia from June 2022 to December 2022, were divided into control group(group C) and esketamine group(group K) using a random number table method, with 47 cases in each group. Midazolamm, sufentanil, etomidate and cisatracurium were intravenously injected for anesthesia induction in both groups, and esketamine 0.5 mg/kg was intravenously injected on this basis in group K. Propofol and remifentanil were intravenously infused to maintain anesthesia, and cisatracurium besylate was intermittently injected to maintain muscle relaxation in both groups, and esketamine 0.25 mg·kg -1·h -1 was intravenously infused on this basis in group K. The patients were connected to an analgesic pump for patient-controlled intravenous analgesia at 10 min before the end of surgery, and flurbiprofen axetil 50 mg was intravenously injected for rescue analgesia when the numeric rating scale score >4. The time of first pressing the analgesia pump, effective pressing times of the analgesia pump within 48 h after operation and requirement for rescue analgesia were recorded. The initial dose of remifentanil, cumulative amount of remifentanil used during operation, time of tracheal extubation, and adverse reactions within 48 h after surgery were recorded. Results:Compared with group C, the cumulative use of remifentanil during operation was significantly reduced, the time of first pressing the self-control button of the analgesia pump after surgery was prolonged, the pressing times of the analgesia pumps were decreased( P<0.05), and no significant change was found in terms of the initial dose of intraoperative remifentanil, rate of postoperative rescue analgesia, time of extubation, and incidence of adverse reactions after surgery in group K( P>0.05). Conclusions:Esketamine-based anesthesia can reduce the amount of intraoperative opioids, delay the time of postoperative pain and reduce the early postoperative pain when used for lumbar spine surgery.