Since the design of gate pier is usually constrained by the stress condition at the neck, the prestress technique becomes an important measure to improve mechanical behavior of the large-sized arch gate pier. One of the most important problems is the anchor block's structure characteristic and its effect on the stress condition at the neck. Through structure simulation model test, we investigated the variations of crack resistance at the neck and stress distribution in the anchor block caused by setting a cavity in the anchor block, and discussed the effect of hollow anchor block on the mechanical behavior of gate pier. The prestressed pier of Pushi River pumped storage power station was taken as a case study. The results showed that the design of the new type hollow anchor block could enhance the prestressed effect at the neck of the pier effectively, and improve the crack resistance of the neck.