The coupling effect between stress and galvanic corrosion on bimetallic screws in the femoral environment was systematically investigated for the sake of providing a theoretical basis for the wear prevention and control of a novel degradable screw used in the treatment of vertical femoral neck fractures (Pauwels type III). A three-dimensional model of the femoral based on the CT data was created. With respect to the assembled screws, three geometric structures were proposed, and two sets of material properties, namely titanium/magnesium alloy (Ti/Mg) and titanium/zinc alloy (Ti/Zn) were assigned to afford different mechanical and electrochemical characteristics (cathode area/anode area ratio (Sc/Sa); potential difference; cathode-anode distance). Through a multi-physics finite element model, the electrochemical corrosion behaviors and stresses of the screws at different degrees were coupled and analyzed. The research results showed that: in the 50-day corrosion process, the Ti/Zn composite screw had the maximum current density and maximum stress of 1.48 A/m2 and 66.16 MPa, respectively, which are 55.69% and 74.94% less than those of the Ti/Mg composite (maximum current density of 3.34 A/m2 and a stress of 264 MPa). An Sc/Sa of 0.43 had the greatest effect on both single corrosion and load-bearing (the maximum current density and maximum stress of this type of screw in the Ti/Mg composite were 0.43 A/m2 and 165 MPa, respectively), lower than that for Sc/Sa values of 3.34 and 1.11, by a significant margin. The stress concentration effect is higher than the yield point of the material (maximum stress of 265 MPa), through an interaction with the corrosion, had a remarkable effect on which the material degradation was strongly accelerated (corresponding to accelerated corrosion thickness of 33 μm). The coupling effect of galvanic corrosion and mechanical stress on the mechanical properties and corrosion resistance of bimetallic materials has a great influence. Optimizing factors such as the geometric structure of the Sc/Sa metal sleeve and the corrosion potential difference can improve the corrosion resistance and mechanical stability of the screw.