To investigate the advantages and disadvantages of the combined anterior-posterior approach to decompression and fixation and the posterior approach to fixation and decompression in the treatment of severe lumbar burst fractures. Methods Forty-four cases of severe lumbar burst fractures treated by combined anterior-posterior approach decompression and fixation method and phase I posterior approach fixation and decompression method were selected from January 2005 to June 2010, including 35 males and 9 females, aged 19-57 years, average 36.6 years; injury sites: 113 cases of lumbar, 221 cases of lumbar, 37 cases of lumbar, 43 cases of lumbar; all were classified according to AO A3.3 type; load score 7 to 9, average 8.2; spinal nerve injury according to Frankel classification: grade A 4 cases, grade B 9 cases, grade C 17 cases, grade D 11 cases, grade E 3 cases; using one-stage posterior pedicle screw fixation and lateral anterior spinal canal decompression and fixation 23 cases, one-stage posterior pedicle screw fixation, spinal canal decompression and anterior mid-column reconstruction of the vertebral body 21 cases. The operative time, intraoperative bleeding, postoperative drainage, and intraoperative and postoperative transfusion of allograft blood were compared between the two groups of cases. The changes in Cobb angle, height recovery of the anterior margin of the injured vertebrae, and spinal canal occupancy were evaluated according to imaging in the two groups of cases before, after, and at the final follow-up. Implant fusion and spinal nerve recovery were observed during the follow-up. The Denis score was used to compare the differences in recovery of local pain and working status between the two groups. Results The differences in operative time, intraoperative bleeding, postoperative drainage and intraoperative and postoperative transfusion of allograft blood were statistically significant between the two groups of cases, and the one-stage posterior approach group was superior to the one-stage combined anterior-posterior approach group. Follow-up was obtained in all cases, and the follow-up time ranged from 12 to 48 months, with a mean of 29.5 months, and no loosening or rupture of the internal fixation occurred in either group. There were no statistically significant differences between the two groups in postoperative Cobb angle correction, recovery of anterior vertebral margin height, recovery of canal occupancy rate, and maintenance of anterior vertebral margin height and canal occupancy at the final follow-up (P>0.05). However, after pedicle screw removal, some cases in the one-stage posterior approach group showed mild loss of correction, whereas cases in the combined anterior-posterior approach group were well maintained. Good implant fusion was obtained in both groups, and their spinal nerve function was well recovered except for those with preoperative grade A. At the final follow-up Denis local pain scores were better in the one-stage posterior approach group than in the combined anterior-posterior approach group, while there was no statistical difference between the two groups in terms of working status. Conclusion For the surgical treatment of severe lumbar burst fractures, the one-stage posterior approach has better advantages than the combined anterior-posterior approach, such as less trauma, less bleeding, and shorter time, but the indications for surgery need to be strictly controlled.