In order to further study the response law of mid-story isolation structure considering SSI effect subjected to three-dimensional long-period earthquake and the difference with ordinary ground motion,one-dimensional,two-dimensional and three-dimensional ordinary ground motions and long-period ground motion are input respectively.Aiming at the more serious stress overrun problem of bearing subjected to three-dimensional long-period earthquake,the reliability of three-dimensional isolation structure subjected to long-period earthquake is further verified by adding three-dimensional isolation bearing.It is found that the seismic response of inter-story isolation structure considering SSI effect is greater than that subjected to ordinary ground motion input under long-period ground motion.The structural seismic response subjected to three-dimensional long-period earthquake is greater than that subjected to one-dimensional and two-di-mensional inputs.The three-dimensional isolation structure can still effectively isolate the vertical earth-quake under the action of long-period earthquake,the bearing stress is effectively reduced,the foundation soil stress is optimized,and the isolation effect is obvious.