In this work, the plastic overstrength behavior of energy-dissipation shear links was experimentally studied. Furthermore, numerical simulations were conducted for analyzing the influences of different parameters on plastic overstrength. The research results indicate that the additional axial tension induced by axial displacement constraint can improve the plastic overstrength of shear links, and with the increase of displacement angle, the improvement shall be more remarkable. With the increase of axial compression, the plastic overstrength of shear links may gradually decrease. The axial tension can improve the plastic overstrength of shear links to some extent, but the improvement tends to be stable after the axial tension ratio exceeds 0.1. The height-thickness ratio of web has little influence on the plastic overstrength. The decrease of aspect ratio of web, stiffener spacing and equivalent link length coefficient eVp/Mp can improve the plastic overstrength. The increase of hardening stress of steel can significantly improve the plastic overstrength. Finally, a theoretical prediction approach for plastic overstrength was proposed, and both experimental and numerical results validated the high accuracy of the proposed approach.