1. A method of rapidly establishing an image spatial relation using planar filtering limitation, comprising the steps of: getting a plurality of continuous image data at different shooting angles such that each image data contains a plurality of feature points; randomly selecting a preset number of feature points from each image data for performing a comparison, where the feature points from the same image data is defined as a compared group; computing an error value from each selected feature point to an epipolar line to produce a plurality of epipolar errors; arranging the epipolar errors in order for finding a median error value among the epipolar errors; determining if the selected feature points are coplanar; when the selected feature points are non-coplanar, then the selected feature points are used to perform an epipolar geometry fundamental matrix computation; and when the selected feature points are coplanar, then the median error value obtained is set as a maximum value.