Embodiments of present invention provide an electronic paper display device and a manufacturing method thereof. The electronic paper display device comprises a substrate, a first conducting layer on the substrate and a slanted microbore layer provided on the first conducting layer. The slanted microbore layer comprises a plurality of slanted microbores of a color, electrophoretic display particles are enclosed within the slanted microbores and have different colors from that of the slanted microbores. Each of the slanted microbores comprises an orifice, slanted bore walls and a bore bottom, the angle between the slanted bore walls and the substrate is less than 90°, and the vertical projection of the orifice onto the surface of the substrate is located outside of the bore bottom of the slanted microbore.