Abstract:A finite element modeling analysis is conducted on the thrust free arch bridge with multi-span spatial shaped rigid-beam flexible-arch composite system. Based on the vibration method, the cable force of suspension rod is tested. Through the comparison of the theoretical cable force with the measured cable force, the stress rule of cable force is analyzed for this kind of complex structural bridge. Meanwhile, based on the testing results of bridge cable force over the years, the change features of cable force with the change of eternal load are studied. The safety and toughness of the health status of bridge cable force under long-term operation are analyzed. By testing the natural vibration characteristics of the bridge, the overall performance of the bridge structure is analyzed, which provides a basis for evaluating the working condition of the bridge.