Abstract: The Xiluodu arch dam is located in the earthquake-prone southwest region, and its seismic analysis and evaluation is of great significance. In this work, a nonlinear damage analysis model of the arch dam-reservoir water-foundation system is used to analyze the influence of canyon contraction on the dynamic response of this dam under different reservoir stages. The results show that the deformation will aggravate plastic damage to the dam at its abutment and in its middle part near the abutment and the orifices, while a high reservoir stage can alleviate the adverse effect of canyon contraction.