To provide an object detection system and object detecting method capable of transmitting parameters such as an offset correction value and a gain correction value to a detecting device, by simple configuration even when an image pickup device and the detecting device are connected only by a video cable corresponding to an analog transmission system.

Image data picked up by a plurality of image pickup devices for performing stereo imaging is acquired, and an object in images is detected. The plurality of image pickup devices calculate one or a plurality of parameters for correcting the image data on the basis of the picked-up images, the parameters are recorded in image data corresponding to an area where the picked-up images do not overlap, and the image data is transmitted to the detecting device. The detecting device receives the image data picked up by the plurality of image pickup devices, extracts the parameters, corrects the received image data on the basis of the extracted parameters and detects an object on the basis of the corrected image data.