To achieve safe and efficient replacement of stay cables that exceeded their designed service life or suffer serious damage, this study proposed a stay-cable replacement system (SRS) which used the existing cable-stayed anchor plate (ECAP) as a reaction force system. The scaled model of the typical main girder segment and the full-scale model of the SRS were designed and produced. The axial compression and eccentric compression static tests were carried out under the conditions of dry contact and adhesive contact between the steel anchor barrel (SAB) of SRS and the ECAP. The results show that, under dry contact conditions, the failure mode of the SAB is the buckling of the contact point between the eccentric compression side of the SAB end and the ECAP; under adhesive contact conditions, the failure mode of the SAB is the buckling at the interface between the eccentric compression side of the SAB and the epoxy resin glue. After pouring of the epoxy resin glue, the displacement and maximum compressive stress of the SAB are smaller, and the compressive safety and stability of the SAB are better. The proposed SRS can be applied in stay-cable replacement.