The present disclosure relates to a light driving apparatus which may stably drive an LED light at a normal operation by feeding back the output voltage of the LED light and stably drive the LED light at an abnormal operation by feeding back the voltage supplied to the LED light, and the light driving apparatus includes: a rectifier circuit; a transformer circuit; a power factor correction circuit; a smoothing circuit; a constant-current driving circuit; a dimming control circuit; a photo-coupler; a sample and hold circuit; a first photo-coupler driving circuit for feeding back the voltage output from the sample and hold circuit and applying the feedback voltage as a driving voltage of the photo-coupler; and a second photo-coupler driving circuit for feeding back the voltage output from the smoothing circuit and supplied to the LED module and supplying the feedback voltage as a driving voltage of the photo-coupler.