Abstract: The ground deck of a certain type of ship experienced abnormal vibration failure during long-term operation. The causes of ground deck abnormal vibration were analyzed by safety evaluation, livability evaluation, spectrum analysis, and structural investigation. The results show that there were a large number of marine organisms attached to the propeller, which increased the surface roughness of the propeller, changed the original associated flow field of the propeller, and subsequently increased the excitation force, ultimately leading to abnormal vibration of the local ground deck.