The present invention provides a discharge lamp lighting device capable of maintaining a stable luminance irrespective of an application environment for a discharge lamp used as a light source for animage forming apparatus having a color wheel. The discharge lamp lighting device includes a pulse generator that is input with a synchronizing signal and generates a pulse wave whose polarity is reversed according to a synchronizing signal that is switched with a color region of an object irradiated with the light from the discharge lamp timing synchronization. The pulse generating unit executes acontrol mode during a single rotation of the color wheel and repeatedly executes the control mode including a first step of reversing a polarity of the pulse wave while the color wheel rotates a predetermined number of revolutions. The second step of maintaining the polarity of the pulse wave. The predetermined number of turns is set to the first number of turns when the frequency of the synchronization signal is a frequency belonging to the first frequency band and is set to be equal to the frequency of the second frequency band belonging to the second frequency band higher than the first frequency band more than the first lap number of the second lap.