Abstract: In order to develop the modeling method for predictions in high-frequency ranges with a random transverse base excitation in the spacecraft environmental test, a finite element model of a typical spacecraft is built and calculated to extract the longitudinal vibration data of the back floor, the flexural vibration data of the connecting ring and vibration table. Furthermore, two different excited SEA models, the longitudinal excitation of the back floor and the bending excitation of the connect ring, are calculated by using the statistical energy analysis method and with the finite element results as the excitation data, the results of two different models are compared. Finally, a modeling approach of the random transverse base excitation of the spacecraft environmental test by using SEA is established. The study shows that the vibration table data obtained from the spacecraft environmental test could be applied as the excitation of the connecting ring in form of the flexural wave to predict the vibration response of the spacecraft in the high-frequency range under the base transverse excitation.