Abstract: In order to solve the problem that the elastic effect, strain rate and strain hardening effect cannot be considered simultaneously in the traditional impact similarity method for elastic-plastic beam and plate structures, a similarity correction method based on elastic-plastic materials is proposed. Based on the existing similarity theory of ideal elastic-plastic materials, the optimum approximation relationship between the yield stress predicted by the proportional model and the original yield stress on the strain rate interval and strain interval is established, and the stress proportional factor between different elastic-plastic materials is obtained directly. The accuracy and applicability of the method are analyzed by using the rectangular beam and circular plate mass impact models. The analysis results show that the modified method can take into account the elastic effect, strain rate effect and strain hardening effect of real metal materials, and has wider applicability and higher accuracy than the existing similarity method.