The utility model discloses a folding chair with X-shaped cross legs, which comprises a backrest, a seat board and a support bracket, wherein the support bracket comprises a pair of front support legs and a pair of rear support legs which are hinged together mutually; the front support legs are pivoted with and support the front end of the seat board; the upper ends of the rear support legs are fixedly connected together with the backrest; a fore-and-aft chute is fixedly formed below the seat board; and a support bar is horizontally connected between the two rear support legs, passes through the chute and supports the rear end of the seat board. In the utility model, the chute is formed below the seat board; and through the folding of the X-shaped support bracket, the seat board can move forward as far as possible when the folding chair is unfolded, so as to increase the sittable area of the chair.