In order to better understand the vibration characteristics of the propeller-shaft system, a propeller-shaft system was taken as the research object, and the simulation analysis was established based on several modules under ANSYS Workbench platform. The vibration of the propeller-shaft system under the scale model was studied considering the water pressure and centrifugal force. The full-size model and the reduced size model were used to investigate the vibration similarity of the propeller-shaft system, and the natural frequency, mode shape and amplitude-frequency curves were solved respectively to verify the similarity. The vibration characteristics of water pressure and centrifugal force were considered in the verified shrinkage model. The open water pressure of the propeller is calculated by using the Fluent module, and then the calculated results are loaded by unidirectional fluid-structure coupling method. The simulation of centrifugal force is realized by setting different rotation speeds. The harmonic response analysis was calculated by the modal superposition method. The results of natural frequency, mode shape and amplitude-frequency curves of the scaling model are basically consistent with those of the original model. When water pressure and centrifugal force are included, the natural frequency of the propeller-shaft system will be reduced. The effect of water pressure has a great influence on the longitudinal natural frequency of the paddle-shaft system. The influence of centrifugal force on the natural frequency of the propeller-shaft system is not obvious.