Objective To investigate the effectiveness of posterior indirect decompression and internal fixation with pedicle screws in treating thoraclumbar burst fracture without spinal cord or nerve damage accompanied with Large bone protruding into the spinal canal. Methods 42 cases were treated with pedicle screw fixation and kept the lamina. Pedicle screws were inserted into injury vertebra and adjacent centrums, and braced them for indirect decompression at the same time. To observe the recovery of injured vertebral height, the correction of segmental kyphosis angle, the restoration of protruding bone fragment and presence of nerve injury symptoms. Results After the operation, the patients were followed up for average 30 months, by comparing indexes between preoperation and postoperation, indirect decompression patient's anterior and posterior flange height of vertebral body was 53.8% and 82.3% vs 91.7% and 95.3%, and the segmental kyphosis angle was 27.1° vs 5.3°, and the cross-sectional area of spinal canal was 51.2% vs 83.7% on average. There was a significant difference between the indexes of before and after the operation. In postoperation follow-up, no patient had delayed neurological damage. Conclusion Pedicle screw internal fixation with indirection decompression is an effective method to treat thoraclumbar burst fracture,with bone fragments in spinal canal and without nervous dysfunction.