In order to accurately identify the damage location and degree of suspension Bridges components, large-span space structure finite element model was established, through the simulation of quasi static loading, the structure of the displacement and stress influence line were extraction and analysis, the curvature difference index of influence line were established, vibration mode and frequency of structure were obtained, the flexibility matrix of suspension bridge structure were computed, and the flexibility curvature difference rate of change were established to identify the damage of suspension bridge structural members. Combining with the index of influence line and flexibility matrix, the identification sensitivity of different positions and degrees in longitudinal lower chord, longitudinal oblique ventral rod and derrick rod damage were studied based on Dempster-Shafer evidence theory. The results show that the damage identification index of compliance curvature difference rate is more sensitive to the damage of suspension bridge members than that of influence line, and the fusion index has higher accuracy than the single damage identification index, and has better robustness in damage location.