Abstract: To enhance the seismic performance of steel plate shear walls (SPSWs) with two-side connection and avoid severe failure caused by "corner instability" of infill steel plate, this paper proposes a lightweight double steel plate sandwiched or externally applied CFRP composite shear wall structure with two-side connection. The proposed design incorporates the concepts of corner reinforcement and FRP-steel laminate strengthening. To fully utilize the energy dissipation potential of double steel plate-CFRP composite wall plate in the stiffened grid, the calculation method of elastic shear buckling stress for double steel plate sandwiched or externally applied CFRP composite shear wall with two-side connection is proposed based on the principle that the global buckling does not precede the local buckling, and the design methods of the stiffeners are developed. Based on this, the quasi-static cyclic loading tests of a hinged frame is designed and completed with double SPSW with two-side connection, double steel plate sandwiched or externally applied CFRP composite shear wall with two-side connection. The study aimed to investigate the seismic performance of the wall plate independently. The results indicate that compared with the pure steel plate structure, the double steel plate-CFRP composite shear wall with two-side connection effectively enhances the seismic performance of the structure, and the initial stiffness, peak bearing capacity, and cumulative energy dissipation of the specimen by laying the ±45° CFRP externally and corner reinforcement are increased by 38.31%, 33.95%, and 20.40%, respectively; Due to the reduction in structural ductility resulting from corner failure, the bearing capacity of the sandwiched ±45° CFRP specimen are degraded close to that of the pure steel plate specimen when the inter-storey displacement angle reaches 1/50; The out-of-plane maximum deformation of the double steel plate sandwiched or externally applied CFRP reinforced specimens is reduced by 87.63% and 89.80%, respectively, compared with the pure steel plate specimen. This shows that arranging ±45° CFRP layers can effectively restrain the out-of-plane buckling deformation of the wall plates.