The invention relates to a heating type mold of an aluminum alloy flange plate through a heating pipe and an extrusion molding method thereof, belongs to the field of aluminum alloy hot processing, and is suitable for hot extrusion and forming of aluminum alloy flange plates for aerospace. The heating type mold comprises an upper mold, a lower mold, an upper push rod, a lower push rod, a lower mold base plate, a connecting bolt and hoisting suspension rings. The extrusion molding method comprises the following steps of I, according to a constant volume principle and technology allowance, determining the diameter of a blank and preparing the blank; II, after the mold is assembled, fixing the assembled mold to a press machine platform; III, assembling the heating pipe, a temperature thermocouple and a heat preservation partition board to corresponding positions on the mold; IV, respectively heating the mold and the blank to a set temperature, and performing heat preservation for some time; and V, placing the blank in a lower mold cavity, closing the upper mold and the lower mold, so as to realize the hot extrusion forming of the flange plates, and enabling the lower push rod to drivethe upper push rod to eject a formed piece, so that the forming of the flange plate is completed. The flange plate formed by the extrusion molding method disclosed by the invention is high in material utilization rate, high in forming efficiency, small in burrs, good in product consistency, high in dimension accuracy, high in profile accuracy and good in surface quality.