An exposure adjustment method for night-vision camera includes the following steps. A first image and a second image are shot with an infrared light source of different intensity; the shot first image and second image are divided into a plurality of image blocks, in which positions of the image blocks in the first image are respectively corresponding to those in the second image; a light reflectivity of the image blocks of the first image is compared with a light reflectivity of the image blocks of the second image, and object distances of image objects are determined; the image object having greater object distance obtains a lower light measuring weight, and the image object having smaller object distance obtains a higher light measuring weight; and an exposure parameter of image images is adjusted according to the image weights of the two images and light measuring weights of the blocks.