Objective: To investigate the effect of different internal fixations in lamina replantation and spinal canal reconstruction on lumbar range of motion (ROM) by using finite element method. Methods: The lumbar L2-4 segment finite element model was established and compared with in vitro experimental data to verify the validity of the model. According to the different treatment methods, the research were divided into normal assignment model group, laminectomy group, H-shaped Titanium plate group, L-shaped Titanium plate group, and two-hole Titanium plate group. The same boundary loading was applied to the various finite element models and the ROM of lumbar L2-3 and lumbar L3-4 were compared under six conditions including flexion, extension, left and right bending, left and right rotation. Results: The validity was verified and the lumbar L2-4 segment finite element model could be used in experimental studies. the ROM of lumbar L2-3 was greater than that of normal assignment model group only under flexion loading condition (P<0.05). No significant difference in the ROM of lumbar L2-3 was found between normal assignment model group and L-shaped Titanium plate group or two-hole Titanium plate group under the loading conditions of extension and right bending (P>0.05), while there was no statistically significant difference in the ROM of lumbar L3-4 under flexion loading condition (P>0.05).The ROM of lumbar L2-3 in L-shaped Titanium plate group or two-hole Titanium plate group were greater than that of H-shaped Titanium plate group under the loading conditions of left and right bending, left and right rotation (P<0.05), while The ROM of lumbar L3-4 was greater than that of H-shaped Titanium plate group under the loading condition of left bending, left and right rotation (P<0.05). The ROM of lumbar L3-4 in two-hole Titanium plate group were greater than that of H-shaped Titanium plate group only under the right rotation loading condition(P<0.05). Conclusion: The application of lamina replantation and spinal canal reconstruction can effectively reduce the ROM of spinal segment and maintain its biomechanical stability. Lamina replantation and spinal canal reconstruction with H-shaped Titanium was significantly better than that of L-shaped Titanium plate and two-hole Titanium plate under bending and rotation.