Abstract: This article uses typical examples to show that key dimensionless intrinsic parameters may exist in some problems of engineering plasticity and structural impact dynamics, which govern the response mode and major deformation characteristics of the solid/structure. Therefore, if this kind of dimensionless intrinsic parameters can be consciously found, identified and refined in the process of non-dimensionalization and theoretical modeling, it will be of great significance for understanding the deformation mechanisms and predicting the mechanical behavior of structures under extreme conditions, as well as for selecting materials, configurations and main geometric parameters in the early stages of design.