Objective Quantitative biomechanical compairson of different internal fixation methods for distal femoral fractures provides theoretical basis for clinic curing. Method Performing theoretical and experimental stress analysis for fixing Y type femora fracture by using three different internal fixation methods. Results Under the same load condition Intramedullary supracondylar nail method is the best while for comprssed plate method the femoral condyle strength and origidity is worse (P<0.05). Conclusion Intramedullary Supracondylar nail Method is the best method among different internal fixation methods. It deserves to be put into application and populatization.