Objective To investigate the effectiveness of one-hole split endoscope (OSE) technique in the treatment of single segment lumbar spinal stenosis (LSS). Methods The clinical data of 32 single segment LSS patients treated with OSE technique for simple spinal canal decompression between January 2022 and December 2022, who met the selection criteria, were retrospectively analysed. There were 18 males and 14 females, the age ranged from 45 to 82 years, with an average of 65.1 years. The disease duration was 9-72 months, with an average of 34.9 months. The surgical segments included L3, 4 in 3 cases, L4, 5 in 19 cases, and L5, S1 in 10 cases. The incision length, operation time, intraoperative blood loss, intraoperative radiation exposure frequency, postoperative mobilization time, and the area of the patient’s lesion segment dural sac before operation and at 1 month after operation were recorded. Low back pain and leg pain were assessed by visual analogue scale (VAS) score before operation and at 3 days, 3 months, and 12 months after operation; functional recovery was assessed by Oswestry disability index (ODI) before operation and at 3 months and 12 months after operation; the effectiveness was assessed by modified MacNab criteria at last follow-up. Results All 32 patients successfully completed the operation, with an average incision length of 2.05 cm, an average operation time of 88.59 minutes, an average intraoperative blood loss of 46.72 mL, an average intraoperative radiation exposure frequency of 3.84 times, and an average postoperative mobilization time of 11.66 hours. All patients were followed up 12-16 months, with an average of 13.5 months. One patient experienced lower limb numbness, pain, and decreased muscle strength after operation, while the remaining patients did not experience complications such as dural tear or important nerve damage. The VAS scores of low back pain and leg pain and ODI in patients at various time points after operation were significantly better than preoperative ones, and each indicator further improved with time. The differences between time points were significant (P<0.05). At 1 month after operation, the area of the patient’s lesion segment dural sac was (123.13±19.66) mm2, which significantly increased compared to preoperative (51.25±9.50) mm2 (t=−18.616, P<0.001). At last follow-up, the improved MacNab criteria were used to evaluate the effectiveness, with 18 cases achieving excellent results, 11 cases being good, and 3 cases being fair, with an excellent and good rate of 90.6%. ConclusionThe effectiveness of using OSE technique for simple spinal canal decompression treatment of single segment LSS is satisfactory, with the advantages of minimal surgical trauma and fast recovery.