A temperature detecting device is cooperated with an air conditioner. The temperature detecting device includes a temperature detector and a visual indicator. The temperature detector is utilized to generate a temperature distribution result about a specific area. The visual indicator is electrically connected to the temperature detector and utilized to provide a visual mark indicating position information according to the temperature distribution result. The conditioner includes an air supply module, a wind adjustment module and a detection camera. The wind adjustment module is adapted to adjust wind's direction from the air supply module. The detection camera is electrically connected with the wind adjustment module and adapted to detect the visual mark for controlling the wind adjustment module.