Research conclusions: By using the ANSYS9． 0 program for modeling，the I － level lane load was imposed and the calculation and analysis were made for the nine construction phases． By using the changes of the cross － section deflection，the upper and lower edge stress of the middle cross － section and the upper and lower edge stress of the bearing cross － section，the damage influence of the prestressed strand in hogging moment zone of outside beam on the bridge structure was evaluated． From the calculation it was known there was a little influence of such kind damage on the bridge structure and only some cracks would happen on the concrete protection wall in bearing place．