Objective To provide the basis for optimizing and improving the axial mechanical performance of the posterior pedicle fixation system. The factors that affect the axial mechanical performance of the posterior pedicle fixation system have been Analyzed. Methods The paper establishes a mechanical model of the axial mechanical properties of the posterior pedicle fixation system and performs mechanical analysis. Referring to the YY/T 0961-2014, the axial ejection force test and the axial clamping torque test of JHL-I multi-axis components, JHL-I single-axis components, JHL-V multi-axis components and JHL-V single-axis components are tested through Instron E3000 and Instron E10000. Results According to theoretical analysis and test, The component-ejection-rigidity of the single-axis has been significantly higher than that of the multi-axis; The component-torsion-rigidity of JHL-V has been higher than that of JHL-I; The type and size of the locking bolt and the locking torque of the locking bolt have been the main factors affecting the axial ejection force of the posterior spinal pedicle fixation system; The size of the locking bolt and the diameter of the connection rod have been the main factors affection the axial clamping torque of the system; The axial mechanical properties of the system can be improved by increasing the diameter of the connecting rod, increasing the coefficient of friction between each connecting element, and increasing the pitch diameter of the locking bolt. The research results have provided references and directions for optimizing and improving the axial mechanical properties of the posterior pedicle fixation system.