Provided are a stereo vision system and a control method thereof. A stereo vision system includes an image information extracting unit receiving left and right images of the left and right stereo cameras to extract color information for a brightness control of the images from the received images, an image preprocessing unit performing a process for reducing noises of the left and right images using the color information and a prestored calibration parameter, a stereo matching unit performing stereo matching of the left and right images processed by the image preprocessing unit through an algorithm to obtain a depth map, and a matching result measuring unit receiving the depth map obtained by the stereo matching unit to measure a matching degree, and changing the prestored calibration parameter according to a result of the measurement.