Abstract: Currently, there is a lack of loosening fault detection in the area of transformer bushing turret. Existing structural loosening detections based on vibration signals require a large number of measurement points. In order to improve the two problems, the modal and vibration distribution characteristics of the elongated cantilever beam structure in the area of the bushing turret are studied by simulations and experiments. The effect of loosening faults on modals and on vibration characteristics are analyzed. Vibration characteristic parameters are derived. The fault identification accuracy of each characteristic parameter at different measurement points is compared. The results show that the most accurate detection method of loosening faults in the area of transformer bushing turret is achieved by the 100 Hz/200 Hz vibration amplitude ratio at the antinode of 100 Hz ODS, with an accuracy of 98.08%. This characteristic parameter can also be used in the loosening fault detection of other electrical and mechanical equipment. For equipment with slender structures that is continuously vibrating, it is recommended to use the vibration ratio of the fundamental and diode frequencies at the antinode of the fundamental frequency ODS to detect loosening faults, which can reduce the required measurement points in the loosening fault detection.