Objective To compare biomechanical effects of Zero-Profile anterior cervical intervertebral fusion system and Cage-Plate fusion system on the adjacent segments, so as to provide references for the long-term clinical efficacy of single segment cervical spondylosis. Methods The finite element model of cervical spine C1-7 was established based on CT scan data of normal people. After the validity of the model was validated, two finite element models of C5-6 segment implanted with Zero-P fusion system and Cage-Plate fusion system were built. The physiological torque 1.5 N·m was loaded respectively on the normal model, Zero-P implanted model and Cage-Plate implanted model to simulate cervical flexion, extension, lateral bending and rotation. Changes in the ranges of motion (ROMs) of adjacent segments and stresses on nucleus pulposus, endplate and annulus, facet joints of intervertebral disc were compared for the three models. Results After the two kinds of anterior cervical intervertebral fusion systems were implanted, ROMs of C4-5 segments increased by 20%, but ROMs of C6-7 segments increased up to 120%. The stresses on C4-5 nucleus increased by 78%, while the stresses on C6-7 nucleus increased up to 110%. The stresses on the adjacent endplates and the fiber ring also increased. Conclusions The implantation of Cage-Plate and Zero-P fusion system both increased the ROMs of the adjacent segments, and the stresses on annulus, fiber rings and facet joints of the adjacent discs increased as well, which would cause lesions of the adjacent segments in the long run. However, there was no essential difference in biomechanical effects of the Cage-Plate and Zero-P cage fusion system on the adjacent segments.