Objective <p>To explore the learning curve and clinical efficacy of the unilateral biportal endoscopy (UBE) technique applied in the lumbar disc herniation combined with spinal stenosis.</p> Methods <p>A retrospective study was conducted on 112 consecutive cases of lumbar disc herniation combined with spinal stenosis who received UBE at the Beijing Luhe Hospital, Capital Medical University from December 2022 to January 2024. The cohort was divided into the early group and the late group by using the cumulative summation (CUSUM). The baseline data, surgery-related data, visual analogue scale (VAS) scores, Oswestry disability index (ODI) scores and complications of the two groups were statistically compared.</p> Results <p>Taking the cutoff point of the learning curve as the grouping basis, patients were divided into the early group (25 cases) and the late group (87 cases), with the coefficient of determination R² = 0.98. The comparison of baseline data, ODI scores and complications between the two groups of patients was not statistically significant (<i>P</i> &gt; 0.05). The average operation time and single incision length in the late group were shorter than those in the early group, with a statistically significant (<i>P</i> &lt; 0.05). In addition, compared with the early group, the average postoperative one-month VAS score of the late group significantly decreased (<i>P</i> &lt; 0.05).</p> Conclusions <p>UBE for the treatment of lumbar disc herniation combined with spinal stenosis can relieve pain, alleviate short-term symptoms, and reduce the operative time with clinical experience accumulated. The learning curve analysis in this study revealed that the operative competence in treating these complicated cases was obtained after primary attempt of twenty-five cases.</p>