Objective Analyze the mechanical performance of TT and MCBT on osteoporotic vertebrae through finite element analysis.Methods Osteoporosis specimens provided by the Anatomy Laboratory of Xinjiang Medical University (T value of bone density <-0.25 SD). The L4 vertebral body was scanned by CT and imported into Mimics to establish a three-dimensional model，and finite element analysis was performed by Abaqus.PS and MCBT were used on both sides of the lumbar spine to simulate the placement of screws. The pull-out strength and the load-displacement ratio under the four working conditions of the upper, down, left and right of the two screws were analyzed and compared to evaluate the stability of the screw . And the load-displacement ratio of the vertebral body in the four working conditions of flexion, extension, axial rotation, and lateral flexion to evaluate the stability of the vertebral body. Results ①Pull-out strength: PS pull-out strength is (1431.75±35.51)N, and MCBT pull-out strength is (1620±81.33)N, which is increased by about 13.1% (t=-4.242, p=0.005).②Screw stability: The load-displacement ratio of the MCBT screw is significantly higher than that of the PS under the three working conditions (upper, down, left), which is increased by about 57.2%, 32.4%, and 31.6%.Under the right working condition, there was no statistical difference between the MCBT and PS (t=-1.042，p=0.337).③Vertebral body stability: The MCBT construct had superior resistance to lateral bending (t=-3.039,p=0.023) and axial rotation (t=-5.378,p=0.031) and inferior resistance to flexion (t=0.094，p=0.929) and extension (t=-1.051,p=0.334). Conclusions This experiment shows that comparing with the TT , the MCBT has greater pullout resistance and screw stability, and the vertebral body stability of the MCBT is better than that of the TT in axial rotation and lateral flexion,which demonstrates the superiority of MCBT under osteoporotic conditions and lays the foundation for the clinical application of MCBT .