A physical model for high-piled wharf is established to perform experimental study on the model under ambient excitation. The modal identification procedures are written by the modal identification method NExT-ERA to identify modal parameters of the physical model. The results show that the values from these two methods are very close and the error is very small, which shows the application of the modal identification method NExT-ERA to the modal identification of high-piled wharf under ambient excitation. From the experimental results, it is found that the structural dynamic response signals under ambient excitation is weak, higher order modes of structure are usually difficult to excite, and the modal parameters identified by some data are usually missing, thus it is necessary to perform the analysis combined with finite element model.