Abstract: Damage has a direct impact on the modal parameters of structures. However, finding the location and severity of damage according to the modal parameter change is a challenging task. This is because the structure damage identification problems are in general highly undetermined. The multi-scenario-based structure damage identification method is put forward in this paper. It overcomes this problem by reducing the number of damage locations. First, a high-validated FEM model is obtained by correcting the FE-geometry using a high fidelity geometrical description of the test structure. Then the updated model is used to predict the effect of these damage scenarios on the modal parameters. Thus the damage detection problem can be redefined as a decomposition problem, namely the observed shift of the modal parameters can be decomposed into the contributions of the considered damage scenarios. Finally, validity of this method is verified with a case.