Ultrahigh voltage (UHV) transformer bushings have high seismic vulnerability. A realtime damage detection method is proposed on the basis of acceleration response signals of the bushing in this study to investigate damage detection for bushings when structural damage occurs under earthquakes. High-pass filtering and ensemble empirical mode decomposition were used to extract abnormal high-frequency components of signals as damage characteristics, and the highfrequency energy ratio was defined for the damage localization. A numerical case was conducted to simulate seismic responses of the structure under different damage scenarios, and the accuracy of the proposed method was verified. Research results show that the sudden damage to the structure during the earthquake will produce instantaneous high-frequency components in the acceleration response signal. The energy of instantaneous high-frequency components in the signal is related to the distance from the sampling point to the damage location. The energy will increase when the sampling point is close to the damaged location. Additionally, the data input of the proposed method includes acceleration responses of the structure for damage identification and localization, which are simple data types.