Safety fixing device for civil air defense door in metro section

The invention relates to a subway section civil air defense door safety fixing device, and belongs to the technical field of protective doors. The door comprises a large door leaf and a small door leaf hinged to the upper portion of the large door leaf, and further comprises a limiting bolt used for fixing the small door leaf to be in an open state, a supporting frame is arranged on the large door leaf and located below the small door leaf, the limiting bolt comprises a positioning shaft and a driving piece, the positioning shaft is arranged on the supporting frame, and the driving piece is arranged on the positioning shaft. A positioning groove matched with the positioning shaft is formed in the lower end of the small door leaf, the driving piece is arranged on the supporting frame and connected with the positioning shaft, and the driving piece is used for enabling the positioning shaft to be close to or away from the small door leaf. The small door leaf fixing device has the effect of conveniently fixing th