Abstract: In order to evaluate the floor design response spectrum of the proposed base-isolated structure, a real-time hybrid test system for the isolated structure-equipment combination system was established. A single isolation bearing was used as the test substructure, and the rest of the system was used as the numerical substructure. Considering the main factors affecting the floor response spectrum of the isolated structure, real-time hybrid tests were carried out on six different isolated structure-equipment combination systems. The accuracy and reliability of the floor design response spectrum were evaluated by comparing the floor design response spectrum with the test floor mean spectrum. The test results show that the established real-time hybrid test system of isolation structure-equipment combination system can consider the interaction between isolation structure and equipment, and realize the seismic response test of the seismic isolation structure-equipment combination system under more cases. Moreover, the peak error of the command displacement and measured displacement is under 0.2%, and the peak error of restoring force of the bearing is less than 5%, indicating that the error of the real-time hybrid test is small and the test results are credible. The spectral type of the floor design response spectrum of the isolated structure is basically consistent with the floor mean spectrum obtained from the test, and the values of the main characteristic parameters are the same as those of the floor mean spectrum obtained by the test. Except for the spectral peak, the spectral value of the proposed floor design response spectrum is greater than that of the floor mean spectrum, and the average error of each periodic point is less than 5%, indicating that the proposed floor design response spectrum value of the isolated structure is conservative and accurate.