Abstract: The inter-story isolation technology is a new control method in the field of earthquake engineering. The analysis model of the inter-story isolation hybrid control system with an attached inerter is established. The dynamic characteristic formulae of the inter-story isolation hybrid control system with an attached inerter are derived. The influence of the calculated parameters of the model on the dynamic characteristics is analyzed. The seismic response prediction formula based on the response spectrum is established and verified by time-history response analysis. The response control effect of the hybrid control system with an additional inerter and the influence of key parameters on control effect are analyzed. The results show that the inerter has a certain contribution to the control of the seismic response of the inter-story isolation structures. The proposed method can be used to predict the seismic response of the inter-story isolation hybrid control system with an attached inerter. The inerter can realize the dual control target of both displacement and acceleration. The results provide a reference for the simplified analysis methods and hybrid control of inter-story isolation systems.