1. A matching search method for a stereo matching system, the matching search method comprising: generating a plurality of offset image blocks by shifting a first image block by a plurality of offset values, wherein the first image block is a part of a first image captured at a right view or a left view to an object and each of the offset image blocks comprises a partial of the first image block and predetermined image data; comparing each of the offset image blocks to a second image block, which is a part of a second image captured at the other side of view to the object with respect to the first image, so as to determine, from the offset image blocks, a first offset image block which is the most similar to the second image block; obtaining a global offset of the first image block relative to the second image block, wherein the global offset is the offset of the most similar first offset image block relative to the second image block; performing a matching search for the first offset image block relative to the second image block to generate a matching search result; and obtaining disparity information according to the matching search result and the global offset.