An auxiliary tool for steel structure construction hoisting is formed by assembling a first clamping plate (1) and a second clamping plate (2). The first clamping plate is a steel plate piece with a transverse clamping groove machined in the middle. The second clamping plate comprises a steel plate piece with the same shape and size as the first clamping plate and a lifting lug (2d) welded to thebottom of the steel plate piece, wherein the transverse clamping groove is machined in the middle. The length of an upper clamping arm of the steel plate piece is smaller than that of a lower clampingarm, a mounting hole is machined in the notch end of the lower clamping arm, clamping notches of the first clamping plate and the second clamping plate are opposite, and the lower clamping arm is inlap joint and connected and fastened through a bolt (3). And the first clamping plate and the second clamping plate are assembled to form a rectangular hoisting tool with a T-shaped groove (4), and the bottom of the hoisting tool is provided with a lifting lug. The steel frame structure inclined support is simple in structure, easy to manufacture and convenient to use, and the trouble that a craneor a tower crane needs to be used for installing the steel frame structure inclined support in the prior art is solved.