Objective To investigate the vulnerable regions of the spinal cord in scoliosis patients under different wedge osteotomy correction angles, determine the appropriate osteotomy angle, and provide quantitative guidance for the biomechanical optimization of osteotomy surgery. Methods A detailed spinal cord and spine model was established and validated. Ten osteotomy correction conditions (0°–50°, at 5° intervals) were simulated to analyze the biomechanical responses of the spinal cord. Results At 45° osteotomy, spinal cord pressure approached the injury threshold (0.00665 MPa), occurring at the gray-white matter interface in the central spinal cord at the osteotomy level. Stress growth rates in gray and white matter decreased before 35° but increased thereafter, with the largest increments (54.4% for gray matter and 51.8% for white matter) observed between 45° and 50° coMPared to 35°–40°. At 45°, the T6 osteotomy segment exhibited 31.7% and 24.5% higher gray matter stress, and 10.5% and 36.1% higher white matter stress coMPared to T5 and T7, respectively. Maximum stress consistently localized to the central gray matter at the osteotomy site, followed by the gray-white matter interface at the anterior convex horn (before 20°) and the central gray-white matter interface (after 20°). Conclusion The central gray matter at the osteotomy site is the most vulnerable region. Intraoperative imaging should prioritize real-time monitoring of this area, followed by the gray-white matter interface. Caution is warranted for osteotomy angles exceeding 35°, with a maximum recommended limit of 45°.