According to the biomechanical principle, 18 specimens of human pelvie were selected from freshcadavers and made into samples for biomechanical laboratory test. Using cadaveric pelvicinstrumented with strain gauges displacement instrument compare five different interfixationresults. Blomechanical studies demonstrated utilizing π- shaped rod and T - shaped plates,sufaficient stability of pelvic ring could be Provided. Its the Strength, rigidity and stability appear tooffer distinct biomechanical advantage over the three interfixation method (P<0.01). BiomechamIcal Parameters were provided the theoretical basis in clinical application of different interfixationfor Vertically unstable pelvic fracture.