Abstract: An innovative self-centering dual system is proposed, consisting of a primary subsystem and a secondary subsystem. The primary subsystem sustains a normal occupancy function and can be simplified as a shear beam, while the secondary subsystem takes on the function of controlling damage modes, and energy dissipation and self-centering, can be simplified as a flexural beam with a variable amount of base rotational restraint. The two beams form a distributed parameter model for the proposed system. Closed solution of the modal equation is derived by solving differential equations. Taking the stiffness ratio between a flexural beam and a shear beam, the stiffness ratio between the flexural beam and the base rotational restraint as parameters, the effects on the eigenvalues, modal shapes, modal participation factors and modal drift are investigated, and the mechanism of controlling damage mode is explained from the dynamic perspective. Using this model, a uniform distribution of interstory drift along the height of the structure can be achieved by choosing reasonable parameters. Computation of structural response by combining the superposition method of its vibration modes, it can facilitate the preliminary design and scheme selection of the proposed system.