In response to the non-uniformity of soil materials and the uncertainty of dynamic parameters, based on the orthogonal experimental method and taking a dam as an example, an equivalent li-near model was used to analyze the sensitivity of equivalent linear model parameters to the vertical seismic peak acceleration and vertical permanent deformation of the dam body. The results indicate that the parameters k₂, n, and λ_max have significant impacts on the vertical seismic peak acceleration of the dam body, with k₂ being the most sensitive, followed by n. The parameters k₂, k₁, and λ_max have significant impacts on the vertical permanent deformation of the dam body, with k₂ being the most sensitive, fo-llowed by k₁.