A depth map generation device for merging multiple depth maps includes at least three image capturers, a depth map generator, and a mixer. The at least three image capturers form at least two image capture pairs. The depth map generator is coupled to the at least three image capturers for generating a depth map corresponding to each image capturer pair of the at least two image capture pairs according to an image pair captured by the each image capturer. The mixer is coupled to the depth map generator for merging at least two depth maps corresponding to the at least two image capturer pairs to generate a final depth map, wherein the at least two depth maps have different characteristics.