The invention relates to an illuminating apparatus and a control method thereof, in particular to an automobile bend road illuminating apparatus and a control method thereof, belonging to the field of automobile illumination. The automobile bend road illuminating apparatus comprises a light source, two wedge prisms which are sequentially arranged in front of the light source and respectively arranged in different driven gears, and driving gears that are meshed with the driven gears and driven by a motor. The invention has the advantages that under the condition that no energy consumption is increased, the illuminating apparatus utilizes the light source of the existing headlight and refraction of 'double-wedge prisms' without whole movement to realize the level steering of upper beam or lower beam of the light and keep light distribution in line with a standard requirement and constant, thus reducing the cost and improving the illuminating effect.