1. A matching search method for performing a matching search from a first image block to a second image block in a stereo matching system, the matching search method comprising: obtaining a global offset of the first image block corresponding to the second image block according to an offset relationship between a first image data of the first image block and a second image data of the second image block; and performing the matching search from the first image block to the second image block according to the global offset and a searching range.