Ship steering gear box

The invention relates to a ship steering gear box, which comprises a three-dimensional mounting seat arranged in a driving platform area, wherein a circular gear is arranged in the three-dimensional mounting seat; the center of the circular gear is connected with a steering wheel through a rotating shaft; the steering wheel is positioned outside the three-dimensional mounting seat; a first rack moving groove is also arranged in the three-dimensional mounting seat; a first rack is arranged in the first rack moving groove; the first rack is meshed with the circular gear; one end of the first rack is connected with a second rack through a push-pull flexible shaft; a second rack is arranged in a second rack moving groove, the second rack moving groove is arranged in a cabin area, a rudder plate shaft is also arranged in the cabin area, a sector gear is fixedly arranged on one side of the upper side of the rudder plate shaft; the sector gear is meshed with the second rack; a rudder plate isarranged below the rudde