Abstract: The present invention relates to a control apparatus and method for automatically turning a street lamp on or off The apparatus includes: a light measuring unit for measuring the external illumination around a street lamp in real time; a light collecting unit for recording the external illumination over a predetermined period to perform periodic updates; a reference illumination calculating unit for analyzing the external illumination to calculate a turn-on brightness level and a turn-off brightness level which are respectively references for output controls for turning the street lamp on and off; and an output controller for comparing the turn-on brightness level, the turn-off brightness level, and the external illumination to control the output power supply voltage for the street lamp.