Abstract: In order to study the influence of wire diameters and nominal densities on the mechanical properties of metallic rubber(MR) cushions in different parameters and preloading conditions, and to verify whether the mechanical properties of metallic rubber cushious stable in preloading conditions, a three-dimensional(3 D) isolation device was proposed based on metallic rubber cushions and springs. Then, vertical isolation shaking table tests were conducted on a scaled isolated transformer model, and the dynamic characteristics of the isolated structure, as well as the vertical acceleration response of the structure under unidirectional or bidirectional input were measured. The results showed that the mechanical properties of metallic rubber under preloading were stable, and the vertical isolation device based on metallic rubber cushions and springs could effectively reduce the natural frequencies of structures and effectively reduce the energy input, and the isolation efficiency increased with the increment of the peak ground acceleration.