Abstract: In order to ensure the consistency of bridge construction alignment and designed alignment and the safety of construction process, the grey system theory was adopted. GM (1,1) Model was established by numerical simulation results of deflection and stress under different working conditions in the process of actual continuous rigid frame bridge construction and measurement results as original differential sequence. Corresponding calculation program was prepared by Matlab as calculation tool. On this account, deflection change and stress change in the process of cantilever construction can be predicted, which can guide the bridge construction. The results indicated that the predicted results were in good agreement with the actual test results. The stress of each section in the construction process was within the designed allowable range. Finally, the bridge alignment was in good agreement with the designed alignment.