Base-suspended pendulum isolation （BSPI） structure is a new type of suspension isolated structural system. Firstly， the configuration of the suspension isolation layer and mechanical model of the BSPI structure are described. Then， the finite element modeling of BSPI structure is verified through comparing with the shaking table test. Finally， the finite element models of the BSPI structure and conventional frame structure are built， and dynamic structural responses of these models are analyzed by performing time-history analysis under different seismic actions. Research results indicate that the lateral stiffness of the BSPI structure is reduced greatly by installing the suspension layer， and the acceleration response of BSPI structure is significantly reduced under rare earthquakes， which is only 1/5~1/2 of that of a conventional frame. The displacement response of BSPI structure can be effectively controlled by dampers， and it is reduced to 50% of that of uncontrolled BSPI structure under rare earthquakes. The interlayer displacement of the upper structure of controlled BSPI structure is less than 1/100， which meets the seismic fortification goal.