To investigate the clinical effectiveness of Arthroscopic-assisted Uni-portal Spinal Surgery (AUSS) in the treatment of lumbar spinal stenosis.A total of 475 patients with lumbar spinal stenosis from January 2019 to January 2023 were included in this study. Among them, 240 patients were treated with AUSS (AUSS group); the other 235 patients were treated with unilateral bi-portal endoscopy treatment (UBE group). The differences in surgery-related clinical indicators, pain degree before and after surgery, Oswestry Disability Index (ODI), CT imaging parameters of spinal stenosis, and clinical efficacy were compared between the two groups.Patients in the AUSS group had a shorter operative time than those in the UBE group, and the length of incision and surgical bleeding were less than those in the UBE group, with statistically significant differences (P < 0.05). Before operation, there was no significant difference in the VAS score of low back pain and leg pain between the two groups (P > 0. 05). After operation, patients in both groups showed a significant reduction in low back and leg pain, and their VAS scores were significantly lower than before the operation (P < 0.05). Three months after surgery, the results of CT re-examination in both groups showed that the spinal stenosis of the patients was well improved, and the measurements of lumbar spinal interspace APDC, CAC, ICA, CAD and LAC were significantly higher than those before surgery (P < 0. 05). Besides, the lumbar function of patients improved significantly in both groups, and ODI measurements were significantly lower than those before surgery (P < 0.05).Both AUSS and UBE with unilateral laminotomy for bilateral decompression can achieve good clinical results in the treatment of lumbar spinal stenosis, but the former has the advantages of simpler operation, shorter operation time, shorter incision length, and less surgical blood loss.© 2024. The Author(s).