In order to better understand the vibration characteristics of propeller-shaft system, a paddle-shaft system is taken as the research object, the simulation analysis is established based on several modules on the ANSYS Workbench platform, and the vibration of propeller-shaft system in the scale model with consideration of water pressure and centrifugal force is studied. The vibration similarity of propeller-shaft system is studied with the full-size model and scale model, and the natural frequency, vibration mode and amplitude-frequency curves are solved respectively to verify the similarity. The verified scale model is used to study the vibration characteristics with consideration of water pressure and centrifugal force. The water pressure is used to make the propeller open-water calculation with the Fluent module. The calculation results are loaded with the unidirectional fluid-solid coupling method. The centrifugal force simulation is realized by setting different rotation speeds. The harmonic response analysis is calculated with the modal superposition method. The research shows that the results of scale model on the natural frequency, vibration mode, and amplitude-frequency curves are in agreement with the calculation results of full-size model. The natural frequency of propeller-shaft system with consideration of water pressure and centrifugal force is reduced. The influence of water pressure on the longitudinal natural frequency of propeller-shaft system is greater. The influence of centrifugal force on the natural frequency of propeller-shaft system is not obvious.