[Purpose]To observe the efficacy of posterior long segmental fixation combined with intertrochanteric bone grafting for the treatment of ankylosing spinal disease with hyperextension fracture in thoracolumbar. [Methods] A total of 28 patients with ankylosing spinal disease combined with hyperextension fracture in thoracolumbar admitted to our hospital from 2012~01 to 2016~12 were retrospectively analyzed, All of whom were treated by posterior long segmental fixation combined with intertrochanteric bone grafting. The average age was 55.25±21.84 years old. The American Spinal Cord Injury Association (ASIA) neurological impairment scale was used to evaluate the function of spinal cord preoperatively and postoperatively. The visual analog scale (VAS) and Oswestry dysfunction index (ODI) were used to assess the pain and functional improvement of the patients. All patients underwent X-ray, three-dimensional CT and MRI before and after operation. The pre- and post-operative LKA, AVH, PVH were measured, and the bone graft fusion effect was evaluated according to the 1995 Bridwell interbody fusion grading system. [Results] All the 28 patients were followed up, that achieved complete fusion and fracture healing between the fracture ends. There were no internal fixation loosening and broken nails. The VAS score and ODI index were significantly improved after operation and at the last follow-up, and the difference was statistically significant (P<0.001). [Conclusion] Posterior long segmental fixation combined with intertrochanteric bone grafting for the treatment of ASD combined with hyperextention fracture in thoracolumbar are effective, which promotes fracture healing and reduces spinal injury deterioration, internal fixation loosening and broken nails, and works on kyphosis with high safety and feasibility.