The structural difference between floating shock platform and real ship makes it difficult to establish the corresponding relations of shock environment between the two. In order to make the device impact ability getting from the floating shock platform at different working conditions can react to the impact resistance of ship equipment from different positions and different displacement, the vertical filtering effect of four different displacement ships subjecting to the underwater explosion shock wave is studied firstly. Then, the discriminant analysis of spectral parameters where floating shock platform connects to the device and the inside and outside bottom of the ship is analyzed using the Fisher method. The rationality of the method is validated finally. The results show that filtering effect is more obvious for the larger displacement hull. The shock environment of deck 1 with no superstructure is more serious than deck 2 and deck 3. The Discrimination method of multivariate statistical analysis can establish a correspondence for shock environment of equipment assessment between real ship and floating shock platform. The result has a certain guiding significance for the assessment of ship equipment in engineering applications.