Objective To explore a easier and more precise method of establishing the finite element model of the reconstruction following resection of peri-acetabular tumors, and the internal fixation system Method Using the CT images scanning from L3 to middle-femur to process and generate the STL model of the pelvis and the internal fixation system by Simplewares, after visual assembling, the whole solid model including the internal fixations were to be set up after repair and optimization by Geomagic, afterwards, the error analysis will be introduced. Eventually following the preprocessing of finite Element Models by Abaqus the final finite element model is established and calculated. Result the finite element model with ligament of the reconstruction following resection of peri-acetabular tumors holds high geometry comparability and precise mechanical similarity. Conclusion The compensation using reconstruction by pedicle screws and rods makes the pathway of mechanical force signal transduction more complete. The structure of the postoperative pelvis is integrity and holds stable mechanical response; the visual assembly simplify the modeling procedure with complicated internal fixation e and the high-precison software of reverse engineering guarantees the accuracy of the model.