The effect of prestressed degree on seismic performance of prestressed concrete pier is studied. The plastic hinge properties is gotten by means of reinforce bilinear model and concrete Kent—R.Park model. The different plastic hinge hysteresisloops are obtained by setting prestressing tendons and changing prestressed degree. The result indicates that prestressed concrete pier can bear more great ultimate bending moment and more large dissipation energy ability than common concrete pier. Within the ultimate compressive strength, with the increase of prestressed degree, its relative ultimate bending moment of the prestressed concrete pier rises, and dissipation energy ability rises.