Abstract: Using finite element analysis software ANSYS, a finite element model of the dead state of the suspension and combined cable-strayed pipeline bridge at construction and after 20 years'service is set up. The first twenty order natural frequencies and vibration modes of the two different models are obtained through modal analysis. The wind-induced vibration analysis is studied based on the modal analysis. The results show that the difference of the fatigue load amplitudes caused by different wind-force is not too big. After serving for 20 years, fatigue load amplitudes of the pipeline and the cable are lower than the allowable fatigue strength. So the wind-induced vibration cannot induce any fatigue failure to the pipeline bridge. But the fatigue load amplitude of pipeline bridge after 20 years is higher than that at construction. Therefore, periodic inspection of the bridge is needed for preventing the fatigue failure of the pipeline bridge.