A novel locking steel door used for a ship comprises a door plate, a door frame, a hinge, a
handle, a connecting rod, a rolling head, a pulling
handle, a tapered wedge, a sealing strip, a connecting plate, a transmission shaft and a nut. The
handle, the connecting rod, the rolling head, the pulling handle, the tapered wedge, the connecting plate, the transmission shaft and the nut are matched with one another to be assembled into a locking transmission device. The door plate adopts a
stamping process, regular concave and convex parts are arranged on the surface of the shape of the door plate, and the door plate is provided with an observation window. According to the novel locking steel door used for the ship, the arrangement of the locking transmission device and the design of the door plate are optimized, so that the weight of the door plate of the steel door is significantly reduced, and opening and closing of the steel door are more convenient; and meanwhile, the strength and the stiffness of the door plate are not reduced, and the locking and unlocking functions as well as the working reliability of the steel door are not affected.