A switched-mode light-emitting diode (LED) display unit satisfying fire-fighting smoke exhaust and ventilation requirements includes an LED display unit, a mounting member, an opening-closing actuator and a pressing member. The LED display unit is mounted on the mounting member and the mounting member is mounted on a display panel by an opening-closing actuator and pressed against the display panel by a pressing member. The switched-mode LED display unit provides the pressing member that works to release the pressed mounting member after obtaining a triggering command and the opening-closing actuator that turns on the LED display unit subsequently, thereby meeting the fire smoke exhaust ventilation requirement of the internal surface or the external surface of a building.