<p>This study verifies the applicability of the tension strip model for coupled steel plate shear wall (C-SPSW) systems and analyzes the effects of steel plate aspect ratio, boundary frame (beam-column connection) conditions, and coupling beam end conditions on structural behavior. Based on existing experimental studies, the nonlinear lateral load–displacement response of the steel plate panels was derived using finite element analysis in ABAQUS. The resulting response was transformed into an equivalent bilinear axial load–displacement relationship and implemented in an ETABS-based tension strip model. Using the validated model, a parametric study was conducted on a three-story structure by varying the steel plate aspect ratio, boundary frame beam end conditions, and coupling beam end conditions. The results indicate that the maximum load capacity increases with higher aspect ratios, while the energy dissipation capacity exhibits a slight decrease. Furthermore, modeling the coupling beam ends as pinned connections reduces both the initial stiffness and the maximum load capacity. Nonlinear dynamic analyses were subsequently performed on eight-story and 16-story buildings incorporating C-SPSW. The results reveal increased story drift in models with pinned coupling beam connections, while all models demonstrated sufficient overstrength relative to the design shear force. Future research should more precisely evaluate the structural behavior and load redistribution mechanisms of the boundary frame under varying coupling beam end conditions. Further analyses incorporating additional parameters and joint configurations are required to expand the scope of design applicability.</p>