Marine gas turbine multi-machine power branch transmission system and operation mode switching method

The invention discloses a marine gas turbine multi-machine power branch transmission system and an operation mode switching method. The transmission system comprises a left transmission first clutch, a left transmission second clutch, a right transmission first clutch, a right transmission second clutch, a left transmission controllable clutch, a right transmission controllable clutch, a left transmission mechanism, a right transmission mechanism and a bridging gear assembly. The left transmission mechanism and the right transmission mechanism are the same in structure and are connected through a bridging gear box, and switching of power branch operation modes is achieved through connection or disconnection of a left transmission controllable clutch and a right transmission controllable clutch. The bridging gear assembly comprises a first bridging gear, a second bridging gear and two idle gears which are respectively mounted on respective transmission shafts; the first bridging gear is meshed with one idle ge