The invention discloses a wind power generation and water flow power generation buoy capable of being used for seawater desalination, belonging to the field of seawater desalination. The wind power generation and water flow power generation buoy capable of being used for seawater desalination mainly comprises a water storage vat, a buoy light, a reverse osmosis (RO) mechanism, a drainage mechanism and a power system, wherein the exterior of the water storage vat is coated with a yellow coat; the buoy light is arranged on the water storage vat; the RO mechanism is formed by wrapping at least three RO balls by a filter screen, is arranged two meters below the water surface and is connected with the water storage vat on the water surface by a return pipe; the drainage mechanism is used for draining desalted water in the water storage vat; the power system is used for providing electric energy for the buoy light and the drainage mechanism. The maritime buoy is combined together with seawater desalination, carries out seawater desalination through RO, has high desalination efficiency, generates electric energy via the power system and then can directly provide power for the buoy light and is suitable to develop and utilize on islands.