The invention relates to a building construction all-steel mold plate, which belongs to the field of building construction. The building construction all-steel mold plate comprises two major parts, namely a mold plate and auxiliary accessories, wherein the mold plate comprises a flat plate, an external corner, an internal corner, a special-shaped plate and a stunt head; the auxiliary accessories comprise a double-back arris, a double-back arris hook, an oblique back arris, an oblique back arris hook, a wall-penetrating bolt, a hook head bolt, a fastening bolt, a fastener, an operation platform frame, an oblique support, a mold plate hanging hook and a door hole mold right angle; and the building construction all-steel mold plate is characterized in that the flat plate is formed by weldinga planar plate with a framework, the framework is formed by assembly welding of rectangular steel pipes, the planar plate is surrounded by the framework, a plurality of horizontal and vertical reinforcing ribs are arranged on one side of the planar plate, the reinforcing ribs are the rectangular steel pipes, and connecting holes are arranged on the framework and the reinforcing ribs. Joint seams are tight, the assembly and the disassembly are flexible, the transportation is convenient, the whole hoisting can be realized by a tower hoist, and bulk assembly and bulk disassembly can also be performed. The torsional deformation due to loading can be avoided, when the mold plates are combined for use, the concrete leakage phenomenon at the junctions can be avoided.