Background <p>Scoliosis correction surgery involves surgical wounds, intense intraoperative stimulation, and severe postoperative pain, often necessitating the use of potent-opioids-based patient-controlled intravenous analgesia (PCIA), which have obvious side effects. An effective pain management strategy with both ensuring sufficient analgesia and minimizing opioid-related adverse effects is an urgent need in clinical practice. The ultrasound-guided erector spinae plane block (ESPB) has been reported to provide effective and safe analgesia in many surgical types. Building on this evidence, we hypothesize that ESPB can significantly reduce postoperative pain scores, decrease perioperative opioid consumption, and mitigate opioid-related side effects when compared to PCIA.</p> Methods <p>This study is a randomized controlled trial designed to test the superiority of ESPB in providing postoperative analgesia compared with PCIA. Forty participants undergoing idiopathic scoliosis surgery will be enrolled and randomly allocated in a 1:1 ratio into either the ESPB group or the PCIA group. The primary outcome is the resting numerical rating scale (NRS) pain score within 2 h postoperatively. The secondary outcomes include perioperative opioid consumption, the incidence of opioid-related adverse effects, and postoperative NRS pain scores on movement.</p> Discussion <p>The study will provide evidence for ESPB as an innovative and effective method for postoperative analgesia in scoliosis correction surgery. The results of this trial will contribute to the development of multimodal analgesia regime for managing spinal surgery.</p> Trial registration <p>The National Institutes of Health Clinical Trials Registry, NCT06728046. Registered on December 6, 2024.</p>