Although it was almost after the Wenchuan earthquake that it began to be popularized in China, isolation is not a new technology, and it appeared very early. The isolation bearing is not an artificial product, it has its advantages and limitations. There is not much criticism about the exaggerated reports of the media, so let's briefly talk about isolation technology. ? To put it bluntly, the isolation bearing is actually no different from the spring of the car, except that the spring of the car is mainly separated by vertical bumps, and the isolation of the building is mainly horizontal ground movement. Its principle can be understood as the standard response spectrum used in China's structural design, and it can be understood as the statistical result of the influence of earthquakes on different periodic systems, which reflects the change of seismic force with the natural vibration period of the system under given seismic intensity, site conditions and structural damping. It can be seen that in a certain period interval (0~0. 1s), the longer the period, the greater the seismic force; In a certain interval (0. 1s to the site characteristic period Tg), the seismic force is the largest and does not change with the period; After a certain period (after the site characteristic period Tg), the longer the period, the smaller the seismic force. ? It can be seen that earthquakes do not treat all buildings equally. Earthquakes are more "cruel" to buildings with shorter periods and more rigid structures. ? Adding a spring, the period of the system formed by the building and the spring is more flexible and longer than that of the single building. If the extended period falls at a lower position in the response spectrum than the original period, the seismic force acting on the structure will be reduced, which is considered to be soft and rigid.