Comprehensive utilization system for marine energy

The invention discloses a comprehensive utilization system for marine energy, which comprises a wind turbine, a wave energy converting device and an ocean current energy converting device, wherein the ocean current energy converting device comprises a plurality of floating platforms which are arranged on the periphery of the wind turbine; the floating platforms have closed tops and opening lower ends; each of the floating platforms is fixedly connected with a vertical column which is fixed on seabed; the floating platforms are communicated through connecting pipes which are mounted on side walls of the floating platforms; air holes are respectively formed at the tops of two floating platforms; one-way ventilating valves in inverse directions are respectively mounted; one floating platform can only suck air while the other floating platform can only discharge air; an air turbine is mounted at the top of the floating platform which can only discharge air; and an output shaft of the floating platform and the output shaft of the ocean current energy converting device realize the power combination through a gear system so as to drive a generator for generating electricity. The three generating forms, namely, marine wind energy, wave energy and ocean current energy, are comprehensively utilized by the system, the complementation of electric power under a complex environment is realized, the stability of power output is ensured and the grid-connection is benefited. Besides, the impact of the wave to a tower and the turbulivity of the ocean current are reduced by the wave energy converting device.