1. A method for automatically cropping image objects, including: an object contour detecting step, for detecting the contour of image objects to generate a binary image by using Modified Laplacian Contour Detector; an image dividing step, for dividing the binary image into a background region and a plurality of non-background regions by using Connected Components Algorithm (CCA); and an image merging step, for merging the closer non-background regions from large to small and determining whether the merging of regions is reasonable for cropping image objects.