A flexible display device includes a flexible display panel including a first side and a second side, wherein the first side is opposite to the second side; a roll-up mechanism including a master shaft for rolling up and unrolling the flexible display panel, wherein the first side of the flexible display panel is fixed to the master shaft; a support mechanism including a plurality of supporting members, wherein the supporting members are articulated each other; wherein the supporting members are stored under the flexible display panel, when the flexible display panel is rolled up; wherein the supporting members are leaned to a backside surface of the flexible display panel, when the flexible display panel is unrolled.