Large-span asymmetric horseshoe-shaped multi-layer truss construction method

The invention discloses a large-span asymmetric horseshoe-shaped multi-layer truss construction method. A truss and a core tube are in butt joint through a cantilever bracket, the cantilever bracket is of a box-shaped structure, and the thickness of a web of an inward-extending cantilever bracket of the truss is different from that of a web of an outward-extending cantilever bracket of the core tube; the truss is assembled on the ground through a positioning jig frame, and the positioning jig frame is provided with a plurality of bearing units which are arranged in a scattered mode. A plurality of lifters mounted at the top of a steel tube column of the core tube are adopted to lift the truss integrally. When the truss is assembled, local fine adjustment is facilitated, precise positioning is achieved, and the assembling precision is improved conveniently; the pre-mounted inward-extending cantilever bracket is in butt joint with the outward-extending cantilever bracket on the core tube, effective measures are