The edge examination is mainly carried on the measure, examination and the localization to image gradation change. Deng interrelatedness analysis method based on marginal check's grey system is obviously superior to other methods. The improvement model based on Deng interrelatedness analysis method, unifies the affine transformation and the least squares method fitting a straight line. To a certain extent, it has overcome proportionality factor influence and the displacement difference of the Deng interrelatedness analysis method. The experiment proves that in the examination peripheral point's continuity, the complete aspect has certain improvement compared to the Deng interrelatedness model examination.