A discharge lamp system includes an AC power source, a rectifier, a power factor correction (PFC) circuit, a half-bridge circuit, and a controller. The AC power source provides an AC power. The rectifier converts the AC power into a DC power. The PFC circuit is electrically coupled to the rectifier and is configured for generating an output voltage. The half-bridge circuit is electrically coupled to the PFC circuit and a discharge lamp, and is configured for converting the output voltage into a voltage required by the discharge lamp. The controller is electrically coupled to the PFC circuit and the half-bridge circuit, and includes a timer for counting time, in which the controller controls the output voltage of the PFC circuit in accordance with a time period counted by the timer.