The Method for Object Based Diagnostic Evaluation (MODE) realize the verification of two fields by identifying objects in each filed, calculating object similarity and drawing a composite similarity between the two fields. Compared with the traditional method, which is known as a point to point method, MODE takes account of spatial location, shape size, and other factors of objects, calculates the similarity with a fuzzy logic algorithm conforming to the subjective judgment, and overcomes the shortcomings of a traditional method, such as high sensitivity to spatial locations and “double punishment.” Case studies are conducted, and the results show that MODE has evident advantages.