Temporary structure is the main risk source of construction site accidents. Previous vibration-based detection methods mainly focus on setting accelerometers on some pre-defined critical areas. However, due to the factors such as nonstandard component erection and uncertainty of the construction site for the temporary structure, the critical areas of the monitoring obtained from the analysis may vary dramatically from the reality. Therefore, this paper proposed a structural damage identification method for temporary structure based on phased-based Eulerian video magnification algorithm, making full use of the advantages of global coverage and efficient monitoring of computer vision technology. The digital image of temporary structure vibration collected by digital camera was firstly processed by phased-based Eulerian video magnification to acquire motion-magnified image sequence in the particular frequency bands. Then, the canny edge detector was employed to identify the edges in the image sequence and eliminate the noise resulting from the magnification. The edges in the image sequence were utilized to acquire time-history data of temporary structure displacement based on the geometry centroid, from which resonant frequencies could be obtained after Fourier transformation, and finally the damage states were identified based on the pre-established damage dynamic fingerprint

database. The applicability of the proposed method was discussed in the context of the frame scaffold experiments with 10 kinds of damage states. By comparing the results between camera measurement and accelerometer measurement, the proposed method can yield satisfactory performance with an average error of 0.95%, fulfilling the accuracy requirements of damage identification.