BACKGROUND:With the improvement of cervical posterior surgical techniques, lateral mass screw fixation technology has been widely used in the reconstruction surgery of the cervical spine for stability. However, currently, the finite element study on the lateral mass screw fixation reconstruction of the cervical spine is rare. OBJECTIVE:To establish a fine normal lower cervical spine (C3-C7 ) three-dimensional finite element model and a reconstructed finite element model with three-segment laminectomy with lateral mass screw fixation. Then, to do an initial biomechanical analysis of the lateral mass screw fixation reconstructed lower cervical finite element model. METHODS:We col ected a normal female volunteer aged 30 years old to do CT scan for the whole cervical spine. The Dicom data were obtained. Then, the CT scanning images were dealt with software Mimics 10.01, Geomagic Studio 12.0, Solidworks2012, HyperMesh 10.1 and Abaqus 6.12 software to build the normal lower cervical spine (C 3-C7 ) finite element model, the laminectomy finite element model and the rebuilt finite element model. At last, we analyzed the stress changes of reconstructed models under the state of flexion, extension, lateral bending and rotational motion. RESULTS AND CONCLUSION:The lower cervical spine finite element model contained 503 911 elements and 93 390 nodes with a fine realistic appearance. It successful y passed the validation. The surgical procedure was completed in the software, and the lateral mass screw fixation reconstruction finite element model has been established. Lateral mass screw fixation system provides good stability for the postoperative finite element model. The activity of rebuilt finite element model is much lower than the normal finite element model. In the extension condition, the stress of lateral mass screw fixation system becomes strong.