An image matching method is utilized for performing a stereo matching from a first image block to a second image block in a stereo matching system. The image matching method includes performing a matching computation from the first image block to the second image block according to a first matching algorithm to generate a first matching result; performing the matching computation between the first image block and the second image block according to a second matching algorithm to generate a second matching result and a third matching result; obtaining a matching error and a matching similarity of the first image block according to the second matching result and the third matching result; and determining a stereo matching result of the first image block according to the matching error and the matching similarity.