Special low-temperature closed, heat-insulating, fireproof and heat-insulating door with hidden door lock

The utility model relates to the field of fireproof heat-insulating doors, and discloses a closed, heat-insulating, fireproof and heat-insulating door special for a hidden door lock at low temperature. One end of the rack is slidably connected with a lock rod through a sliding rail, a lock head is arranged at the tail end of the lock rod, a locking groove matched with the lock head is formed in the surface of the inner side of the door frame, a mounting bottom plate is welded to the position, close to a seam of the door frame, of the upper surface of the door leaf, and a moisture absorption top base is fixedly connected to the upper surface of the mounting bottom plate. The interior of the moisture absorption top base is filled with moisture absorption particles. The whole door lock mechanism is hidden in the door leaf, the shielding panel is covered, and no protruding mechanism is arranged on the door leaf. During working, the main rotating gear is rotated to drive the rack to translate up and down, so that