Disclosed herein is a method of manufacturing a multilayered flexible circuit board. The method of manufacturing a multilayered flexible circuit board may include integrally forming a first flexible printed circuit board and a second flexible printed circuit board divided in a symmetrical shape with respect to a reference line on the same plane to provide an original plate; attaching the first flexible printed circuit board to the second flexible printed circuit board by folding the original plate with respect to the reference line; and electrically connecting the first flexible printed circuit board to the second flexible printed circuit board.