Image flat field correction method and device based on linear fitting

The invention discloses an image flat field correction method and device based on linear fitting. The method comprises the following steps: collecting a plurality of images of a shot object; obtaining an original pixel value of each pixel point in each image; establishing a signal gain matrix and a signal offset matrix acting on each pixel point in each image; according to the original pixel value, the signal gain matrix and the signal offset matrix, establishing a linear equation set about the correction pixel value of each image; performing linear fitting based on a least square method to obtain each signal gain value in the signal gain matrix and each signal offset value in the signal offset matrix; and calculating the correction pixel value of each image according to the signal gain matrix, the signal offset matrix and the system of linear equations obtained by fitting. Performing flat field correction on each image according to the correction pixel value; the method can effectively reduce the production