The invention discloses a display device and a manufacturing method thereof. The display device comprises a first substrate, a second substrate and at least one flexible circuit board, wherein the first substrate and the second substrate are oppositely arranged, the first end of each flexible circuit board is arranged on at least one side of the first substrate, the second end of each flexible circuit board is arranged on the second substrate, and an oblique-plane structure is arranged on the edge of the side, provided with the first end of the flexible circuit board, of the first substrate. In the technical scheme of the display device and the manufacturing method thereof, the oblique-plane structure is arranged on the edge, the phenomenon that each flexible circuit board is damaged by burrs when the edge is a right-angle edge is effectively avoided, buffer rubber adhesion is not needed, accordingly the manufacturing cost is reduced, the product yield is improved, and meanwhile the thickness of the display device is decreased.