A fire-engine exhaust-gas discharge device for a firefighting vehicle in a fire station comprising: a base frame inserted into a guide groove formed in a floor of a garage of the fire station; an elevating frame connected to an upper portion of the base frame so as to be slidable in a vertical direction; a suction hood rotatably connected to an upper end of the elevating frame by a hinge and having a cylindrical shape to define a space therein, the suction hood being formed with a suction hole in one side thereof; a discharge pipe unit having one longitudinal end coupled to the suction hood to communicate with the suction hood and a remaining longitudinal end disposed outside the garage, the discharge pipe unit being configured to guide exhaust gas of the firefighting vehicle in the garage so as to be discharged to an outside of the garage; a discharge fan connected to the discharge pipe unit to generate suction force that causes the exhaust gas to be discharged to the outside of the garage through the discharge pipe unit; an elevating drive device provided on the base frame and connected to the elevating frame to generate drive force that slides the elevating frame in the vertical direction; a rotational connection member having one longitudinal end connected to the base frame and a remaining longitudinal end connected to a remaining side of the suction hood, the rotational connection member being configured to cause the suction hood to rotate about the hinge when the elevating frame is moved upward by the elevating drive device so that the suction hole in the suction hood faces an exhaust port of the firefighting vehicle; a vehicle stopper coupled to the floor of the garage and configured to cause a wheel of the firefighting vehicle to be caught by the vehicle stopper in a state in which the firefighting vehicle is stopped such that the exhaust port thereof is disposed adjacent to an upper front side of the suction hood; a stoppage detection sensor provided on the vehicle stopper to detect whether or not the firefighting vehicle is stopped by the vehicle stopper; a vehicle detection sensor inserted into the guide groove to detect whether or not the firefighting vehicle enters a direction in which the vehicle stopper is provided; and a control unit electrically connected to the discharge fan, the elevating drive device, the stoppage detection sensor, and the vehicle detection sensor and configured to control an operation of the discharge fan and the elevating drive device in response to a signal from the stoppage detection sensor and the vehicle detection sensor or to allow a user to control the operation of the discharge fan and the elevating drive device regardless of the signal from the stoppage detection sensor and the vehicle detection sensor. a base frame inserted into a guide groove formed in a floor of a garage of the fire station; an elevating frame connected to an upper portion of the base frame so as to be slidable in a vertical direction; a suction hood rotatably connected to an upper end of the elevating frame by a hinge and having a cylindrical shape to define a space therein, the suction hood being formed with a suction hole in one side thereof; a discharge pipe unit having one longitudinal end coupled to the suction hood to communicate with the suction hood and a remaining longitudinal end disposed outside the garage, the discharge pipe unit being configured to guide exhaust gas of the firefighting vehicle in the garage so as to be discharged to an outside of the garage; a discharge fan connected to the discharge pipe unit to generate suction force that causes the exhaust gas to be discharged to the outside of the garage through the discharge pipe unit; an elevating drive device provided on the base frame and connected to the elevating frame to generate drive force that slides the elevating frame in the vertical direction; a rotational connection member having one longitudinal end connected to the base frame and a remaining longitudinal end connected to a remaining side of the suction hood, the rotational connection member being configured to cause the suction hood to rotate about the hinge when the elevating frame is moved upward by the elevating drive device so that the suction hole in the suction hood faces an exhaust port of the firefighting vehicle; a vehicle stopper coupled to the floor of the garage and configured to cause a wheel of the firefighting vehicle to be caught by the vehicle stopper in a state in which the firefighting vehicle is stopped such that the exhaust port thereof is disposed adjacent to an upper front side of the suction hood; a stoppage detection sensor provided on the vehicle stopper to detect whether or not the firefighting vehicle is stopped by the vehicle stopper; a vehicle detection sensor inserted into the guide groove to detect whether or not the firefighting vehicle enters a direction in which the vehicle stopper is provided; and a control unit electrically connected to the discharge fan, the elevating drive device, the stoppage detection sensor, and the vehicle detection sensor and configured to control an operation of the discharge fan and the elevating drive device in response to a signal from the stoppage detection sensor and the vehicle detection sensor or to allow a user to control the operation of the discharge fan and the elevating drive device regardless of the signal from the stoppage detection sensor and the vehicle detection sensor.