To maximise the effectiveness of the hybrid coupled wall system, a special connection between replacement coupling beams (RCB) and double skin composite shear walls (DSCSWs) is designed. For structural safety, the RCB-to-DSCSW link's seismic design is essential. This research examines the seismic behaviour of RCB-to-DSCSW couplings. Reversed cyclic stress was applied to two specimens with varied embedded rebar arrangement schemes and one specimen with an embedded steel I-beam. All of the specimens failed in the same manner, primarily as a result of concrete crushing at both ends of the joint, weld tensile fracture, and localised buckling of the steel faceplate. The strength and ductility of connections were significantly impacted by concrete crushing and weld tensile fracture. The concrete was swiftly crushed and the connection specimens reached their maximum load capacity at the current or next stage of weld tensile fracture. Compared to RC constructions, all of the specimens showed lower ductility coefficients. Additionally, these two varieties of embedded rebar connections have equivalent mechanical properties. The connection between the steel I-beams is more initially stiff. With the same rotation of loading, the steel beam's total energy consumption increased. The simplified mechanical model and equations for calculating connection bearing capacity were then developed based on the stress distribution of each component.