The invention relates to a single tunnel protective door or cavern door. The single tunnel protective door or cavern door comprises a door frame and a door leaf connected with the door frame through hinges. The door leaf is of a hollow cuboid structure and is internally provided with an X-shaped connecting rod rotating disk lock and a steel skeleton. The door frame, the hinges and the cuboid structure of the door leaf are prepared through glass fiber reinforced plastics. The door leaf and the door frame which are made of the glass fiber reinforced plastics are adopted, so that the whole tunnel protective door or tunnel cavern door has the advantages of light weight and high strength and is resistant to corrosion and fatigue, good in durability, convenient to maintain and replace and suitable for the complex environment in a tunnel, and the service life of tunnel equipment is greatly prolonged. Further, the external structure of the door frame is improved; the X-shaped connecting rod rotating disk lock is arranged aiming at the single door; the connecting firmness of the door and the door frame is further strengthened; the firm degree of a whole door body is improved; and the fatigue resistance of the tunnel protective door or tunnel cavern door can be greatly improved.