Abstract: Various systematic lumped-parameter modes have been developed in recent studies for efficiently representing the dynamic behaviors of unbounded soil. Those systematic lumped-parameter modes are merely constructed by arranging several spring and damper elements, either connected in series or in parallel. Other than their applications in simplifying the analysis and design, those modes have been also analogized to equivalent electric circuits according to their concise mathematical formulation and simple physical correspondence. Based on these new developments in simulating the lumped-parameter modes with equivalent circuits, this research further considered the inclusion of foundation mass and superstructure to extensively explore the possibility of representing the simulation of a complete soil-structure interaction system with a simple circuit experiment. In this study, foundation mass, single-degree-of-freedom superstructure and multi-degree-of-freedom superstructure were added to the original centralized parameter mode to replace soil, so as to gradually establish the equivalent circuit of the complete soil-structure interaction system, carry out simulation tests under three different seismic spectra, and discuss its accuracy and feasibility. Through the comparison of different systems mentioned above, the error of mechanical analysis and equivalent circuit test results was generally less than 10%, which could prove that the equivalent circuit proposed for the complete soil-structure interaction had good test effect and accuracy.