The invention discloses a method for analyzing a vibration characteristic of optical fiber composite submarine cables under ocean current scour, and relates to submarine cable analysis methods. Submarine cables are laid on a seabed or seabed sludge generally, are subject to mechanical damage under influence of submarine complex terrains, ocean currents, and tide scour, and there is on a visual andeffective method currently. The method includes the following steps: performing finite element modeling of submarine cables under the action of wave force; performing finite element result data extraction and analysis; performing submarine cable vibration analysis; monitoring a submarine cable situation through optical fiber vibration according to a relation among a displacement, the accelerationand the frequency of an optical unit. The technical scheme can perform dynamics finite element analysis under the action of the wave force, can know the stress acted on each layer of the submarine cables, can provide a theoretical basis for monitoring of the working state of submarine cables by using a distributed optical fiber vibration sensing technology, can complete real-time monitoring of submarine cable vibration through the optical fiber sensing technology, is low in cost, can perform off-site determination, is high in efficiency, and is visual and effective in submarine cable research.