Objective To provide the biomechanical basis for ZH transpedicular internal fixator used in thoracolumbarfracture treatment. Methods Trauma models were made from 9 fresh cadavers by Panjabi method and divided into 3 groupswith ZH transpedicular internal fixator, Dick screw and Steffee plate, respectively. To test their biomechanical capability inload-responsive change、centrum intensity、displacement、torsion intensity、stability, rigidity and ultimate strength.Results The results of the test showed that ZH transpedicular internal fixator was much better than the other two oneswith: load-responsive change was much less than that of Dick screw and Steffee plate by 7.2% and 14% at Point A andby 17% and 28% at Point B; Centrum intensity: stress decreased by 7% and 14% at Point A, while at Point B by 17% and29%; The displacement decreased by 24% and 33% vertically, and 40% and 55% horizontally. Conclusions The ZHtranspedicular internal fixator is suitable to popularized in clinic application with its better biomechanical capability.