To　solve　the　difficulty　in　3D　seismic　isolation　of　high-rise　structure,　shaking　table　tests　and　numerical　simulations　under　multi-dimensional　excitation　of　an　aseismic　mega-sub　structure　and　a　mega-sub　structure　based　on　three-dimensional　seismic　isolation　of　sub　structure　were　performed.　Firstly,　prototype　structure,　model　structure　and　shaking　table　test　scheme　were　introduced.　Then,　shaking　table　tests　of　two　model　structures　were　carried　out,　the　structural　seismic　responses　were　measured　and　analyzed,　and　furthermore,　test　results　were　compared　with　numerical　simulation　results.　Finally,　the　multi-dimensional　seismic　response　analyses　on　the　prototype　structure　were　conducted.　Experimental　results　and　simulation　results　show　that　the　natural　vibration　periods　of　structure　in　horizontal　and　vertical　directions　are　prolonged,　although　the　three-dimensional　seismic-isolation　bearings　arranged　beneath　the　base　of　sub　structure　are　different　from　those　seismic　isolations　from　the　perspectives　of　seismic-isolation　forms　and　damping　mechanism.　Simulation　results　agree　well　with　test　results.　Seismic-isolation　sub　structure　has　remarkable　damping　effect　on　the　seismic　response　of　main　structure　under　different　ground　motions.　Three-dimensional　seismic-isolation　bearing　also　has　isolation　effect　on　the　multi-dimensional　seismic　responses　of　sub　structure.　If　displacement　responses　of　seismic-isolation　layers　do　not　exceed　the　width　of　seismic-isolation　joint,　sub　structures　shall　not　collide　with　the　main　structure.　©　2017,　Editorial　Office　of　China　Civil　Engineering　Journal.　All　right　reserved.