Marine gearbox and ship

The utility model belongs to the technical field of marine gearboxes, and discloses a marine gearbox and a ship. The marine gearbox comprises a box body, four clutches, a transmission mechanism and an output shaft, each clutch is coaxially installed on the corresponding pivot joint shaft, the first input shaft is the input shaft of the marine gearbox, and the first clutch, the second clutch, the third clutch and the fourth clutch are sequentially meshed; the transmission mechanism is provided with four second input shafts, and the first clutch, the second clutch, the third clutch and the fourth clutch can be connected with or separated from the corresponding second input shafts; the output shaft is pivoted to the box body; the transmission mechanism further comprises a transmission assembly, any second input shaft can be selected as the input end of the transmission assembly, and the output end of the transmission assembly is an output shaft. And the four clutches are engaged, so that the output shaft rotates