A headlight rotating device includes a carrier pivotally and slidably supported in a housing for supporting a light device, a lever supported in the housing and coupled to the carrier for pivoting and sliding the carrier relative to the housing, and a motor is disposed in the housing and coupled to the lever for rotating the lever to pivot and slide the carrier relative to the housing and for rotating the headlight device of the vehicle in accordance with the movement of the vehicle's steering system and for suitably lighting the environment for the vehicle driver while turning the vehicle, the carrier is adjustable or movable forwardly or rearwardly relative to the housing.