The invention discloses a forging moulding bed for a frame type flange forge piece and a forging forming method. The moulding bed comprises an upper moulding bed and a lower moulding bed, cavities areformed in the front and rear sides of the upper moulding bed and the lower moulding bed, the front and rear cavities of the lower moulding bed are provided with cores, and the core in the front cavity of the lower moulding bed is used for matching with a forging and stamping ring of the front cavity of the upper moulding bed; the shape of the lower edge of a sector of a formed frame type flange forge piece is the same as the shape of the rear cavity of the lower moulding bed and the shape of the lower edge and edges on two sides of a sector of a frame type flange forge piece, the core in therear cavity of the lower moulding bed is used for matching with the ring of the lower edge of the formed sector forged and stamped by the rear cavity of the upper moulding bed and the rear cavity of the lower moulding bed, and the upper edge and the two side edges of the sector of the formed frame type flange forge piece. By means of the moulding bed and the method, forging process can be completed with four heating numbers, forging size and shape are uniform, and qualification rate after the forging process is high.