Objective To study the biomechanical differences between compressed hollow screws and shape memory alloy staples in internal fixation of three joint fusion surgery, and provide reference for the clinical application of shape memory alloy staples.Methods The two-dimensional CT data of the foot of a patient with severe stiffness of horseshoe foot were selected, and a model of three joint fusion was established using Mimics and Geomagic software. And SolidWorks2021 software was used to establish the geometry model of triple joint fusion internal fixation; According to the type and combination of fixed screws used (pressurized hollow screws and shape memory alloy riding nails), there are four fixation schemes: A, B, C, and D;The biomechanical characteristics of different models of internal fixation schemes under neutral physiological loading were simulated and analyzed in Abaqus software.Results The maximum displacement of the fusion surface of the internal fixation model in Scheme D was greater than the maximum displacement of the fusion surface of the compression cannulated screw internal fixation model, and the displacement difference between the fusion surface and the compression cannulated screw internal fixation model was smaller. The displacement of the fusion surface of the internal fixation model in Scheme D was close to the parallel displacement; The maximum Von Mises stress value on the fusion surface of the shape memory alloy cross stitch screw internal fixation model is greater than the maximum Von Mises stress value on the fusion surface end face of the compression hollow screw internal fixation model, making the fusion surface contact closer.Conclusion The application of Option D (internal fixation of the fused surfaces of the talonavicular and calcaneal joints with riding nails and the fused surfaces of the talonavicular joints with compression hollow screws) provides stability of the fused surfaces of the internal fixation after triple-joint fusion and provides them with near-parallel micromovement, which produces appropriate fusion stresses to make fusion end contact closer, promotes the growth of bone scabs, and achieves better fusion results.