Abstract: The design and safety evaluation system of offshore substation platform should be established to satisfy the developing requirement of large-scale offshore wind farm. It’s availability can be verified by model test. Combining the elastic similarity and Froude similarity, the hydro-elastic similarity can be obtained. Based on it, the similar relations among the parameters can be obtained so as to help finishing the design of dynamic model of an offshore substation platform. In the model test, the hydro-elastic similarity is used to ensure the similarity relation of dynamic characteristics and wave loads between prototype and model. Also, the Newton similarity is employed to fulfill the similarity relationship of the ice loads. Using SACS, the finite element models of offshore substation prototype and model are established to analyze the structural responses and dynamic characteristics of them. Compared with the numerical results of prototype and mode test, the hydro-elastic similarity is validated.