A multi-screen display device includes a plurality of display screens and a prism structure optical element disposed between two adjacent display screens. The prism structure optical element includes a substrate and a plurality of prism columns. The substrate includes a first region and a second region adjacent to each other, and the lengths of the first and second regions are respectively La and Lb, and La≥Lb. The prism columns include a plurality of first and second prism columns in the first and second regions respectively. Each first prism columns has two interior angles θa1, θa2, a first surface and a second surface. Each second prism columns has two interior angles θb1, θb2, a third surface and a fourth surface. The second and/or fourth surfaces are light absorbing surfaces, or a roughness of the second and fourth surfaces is greater than that of the first and third surfaces.