The utility model discloses a sideboard fixed ladder's instrument, including sideboard main part, time shape fastener, screw rod and clamp plate, the both sides of sideboard main part one end all areprovided with the fixture block, and the both sides of the sideboard main part other end all are provided with the draw -in groove of mutually supporting with the fixture block, the intermediate position department of sideboard main part one side is vertical evenly to be fixed with the pilot pin, and is fixed with wire rope on the pilot pin, it has the apron through the articulated shaft is articulated to return the one end that the shape fastener is close to the pilot pin, and the top that the apron is close to back on one side of the fastener that appears is fixed with the reservation pieceof mutually supporting with provided groove. The utility model discloses a be provided with draw -in groove and fixture block for the aggregate erection of being convenient for of sideboard main part,it is convenient to use, and the device is through installing back the shape fastener simultaneously, and is provided with the guide rail on the top of returning the shape fastener, makes the screw rod be convenient for slide, thereby is convenient for adjust the distance between two screw rods, is convenient for fix the ladder of different specifications, and the suitability is wider, and it isconvenient to use.