Abstract: A theoretical analysis approach of the compound seismic isolation system consisting of DFPS and dish spring is derived.It starts from the relative kinematic energy theorem in multiply-body dynamics,including the coupling effect of the level vibration and vertical vibration.Computation results show that this system has the necessary isolation capability and reposition capability in both directions;the slipping friction forces at the contacting surface provide the energy dissipation capability.When the slide radius is in the range of 1-2 m and the slipping friction coefficient is about 0.01,the seismic isolation effectiveness can be as high as 85%,while the coupling effect in two directions is so slight that it can be neglected and the dynamic responses can be calculated in each direction,respectively.