Abstract: To address the issue of premature fracture along the principal tensile stress direction in CFRP-steel composite shear walls with a full-surface CFRP layout—a failure mode that compromises aseismic ductility—this study proposes a novel structural configuration involving a modified CFRP layering design and a partial-covering arrangement. Quasi-static tests were designed and conducted on three specimens: a fully bonded CFRP-steel composite shear wall, a partially bonded CFRP-steel composite shear wall with equivalent CFRP material usage, and a bare steel plate shear wall. The aseismic performance indicators and failure mechanisms of the three specimens were compared. Based on validated finite element models, the parametric analyses of key variables were further performed. Subsequently, an analytical method was derived for calculating the ultimate bearing capacity of steel plate shear walls with partially bonded multi-angle CFRP layers. Experimental results indicate that: compared to the bare steel specimen, the partially and fully bonded CFRP specimens exhibit a 20.72% and 24.21% increase in the yield load, respectively, along with a 9.45% and 14.00% improvement in the ultimate load. Additionally, the cumulative energy dissipation rises by 26.94% and 42.54%, respectively. Meanwhile, the ductility coefficients decreased by 8.45% and 20.11%, and out-of-plane displacements were reduced by 45.03% and 43.39%, respectively.