This study investigated the use of electromagnetic multiple tuned mass dampers (EM-MTMDs) to decrease the dynamic responses of building structures when subjected to earthquake ground motions. By using a rotary electromagnetic damper, the vibration energy of each TMD unit is able to be converted into electrical energy. To validate the vibration reduction and energy harvesting abilities of the constructed prototype EM-MTMD, it was installed on a scale-down primary structure. Shaking table tests were classified into three stages. In the first stage, the scale-down primary structure was tested and its dynamic parameters were identified. In the second stage, each of the EM-TMD units underwent harmonic excitations to identify their EM damping ratios. In the third stage, the primary structure was installed with the prototype EM-MTMD under the selected ground motions. The results indicated that the proposed EM-MTMD could decrease the dynamic responses of the primary structure and generate power under earthquake ground motions.