Rail-mounted information projection system for long and large underwater tunnel

The utility model relates to the technical field of tunnel engineering, in particular to a rail-mounted information projection system for a long and large underwater tunnel, a rail-mounted device comprises a rail and a traveling mechanism, the rail is fixedly connected with the inner wall of the tunnel, and the traveling mechanism drives a projection terminal to move along the rail; the fire alarm module is used for monitoring the fire condition in the tunnel in real time and performing corresponding early warning; the projection terminal is used for going to a fire scene for shooting according to the early-warned fire area positioning information, and then movably projecting a fire picture on the inner wall of the tunnel so that people in the tunnel can know the fire condition. When the fire alarm module gives out an early warning, the rail-mounted device automatically positions and moves to an accident site according to the early warning position, shoots an image of the accident site, then moves along a rai