The utility model discloses a type steel supporting frame encorbelments in high altitude, including box roof beam on the adjacent two -layer floor I and box roof beam II about locating respectively, box roof beam I, box roof beam II are fixed on the main part roof beam of upper and lower two -layer floor through burying respectively, and box roof beam I and box roof beam are equipped with a plurality of support columns between II, and one side of box roof beam I, box roof beam II is equipped with the bracing, II welded fastening on lower extreme and the box roof beam of bracing, and I welded fastening on one end and the box roof beam who has outrigger, outrigger is welded to the upper end of bracing, the lower floor is equipped with the door opening, runs through in a plurality of void columns that face of interlayer floor, and it has the shaped steel roof beam the facing of door opening both sides to bury a welded connection through the side between the void column. The beneficial effect of the utility model: support the bearing diagonal with the box roof beam, solved the unable problem with the structural connection of outermost collateral branch strut bearing diagonal, by the triangular support system that support column, bracing and outrigger constitute, the installation is dismantled conveniently, stabilizes, and the construction is simple and convenient, and safe and reliable reduces advantages such as the engineering construction drops into.