Taking the pile supported wharf as research object,we analyze the damage characteristics of the wharf by plastic hinge performance,and establish the models according to the two actual wharf structures.Through the pushover analysis of 24 kinds of working conditions,we apply the finite element software SAP2000 to study the damage characteristics of the wharf structure under different earthquake degrees,and establish the corresponding relationship between the damage degrees and the displacement ductile damage index.The results show that under different intensity earthquake,the main failure forms of wharf are mainly due to the plastic hinge of pile foundation and the lateral displacement of pile top,there are no plastic hinge appeared on the upper structure from the beginning to the final failure;under high intensity earthquake,the development degree of plastic hinge and displacement ductility damage index of the longitudinal direction of the wharf are larger than those of the transverse direction,which indicate that the longitudinal stiffness of the wharf is smaller and the damage is more likely to occur.The seismic damage of the wharf is divided into five degrees through the plastic hinge properties of the pile,which include basically intact,slight damage,medium damage,serious damage and collapse,and the corresponding displacement ductility damage indexes are 0～0.1,0.1～0.35,0.35～0.6,0.6～0.8,＞0.8.