The modal flexibility matrix was established based on the finite element model. The sensitivity analysis，between the modal parameters，natural frequency and the boundary stiffness coefficients，was performed. The sensitivity coefficient matrix for the relationship between the flexibility matrix and the stiffness of the boundary support and the cable of the cable-stayed bridge was then derived. According to the difference value between the measured deflection and the theoretical deflection，the relationship expression between the difference value and the stiffness correction value was established. Subsequently，the scaled structure of the real cable-stayed bridge was used as a verification model. The deflection residual was set as the objective function to modify the finite element model，verifying the feasibility of this model. The calculation results show that the theoretical value of deflection is basically the same as the experimental value after the revising of the model. It can provide reference for the research and application of similar engineering.