In order to improve the performance of whole-spacecraft vibration isolation systems,choosing piezoelectric stacks and viscoelastic material as the active and passive vibration isolation components,an innovative whole-spacecraft hybrid vibration isolation system(WSHVIS)is designed and studied.The finite element method is used to establish the dynamic model of WSHVIS and analyze its frequency response characteristic.According to the analysis results,eigensystem realization algorithm is applied to obtain the minimum-order statespace model of WSHVIS,which is used to design controller.On this basis,off-line simulation and on-line realization for the WSHVIS is performed.The simulation and experimental results showed that WSHVIS can effectively reduce the vibration loads transmitted from launch vehicle to spacecraft.Compared with passive vibration isolation system,the hybrid vibration isolation system has a significant inhibitory effect on the low-frequency vibration components,and can greatly increase the safety and reliability of spacecraft.