Adjustable large-span composite string truss assembling support

The utility model discloses an adjustable large-span composite string truss assembling support which solves the technical problem that stress concentration is prone to being generated when a traditional assembling support is used for on-site construction, assembling and supporting of a large-span composite string truss. Comprising a supporting frame, an upper chord member supporting mechanism arranged on the supporting frame and used for supporting an upper chord member of the composite string truss, and a lower chord member supporting mechanism arranged on the supporting frame and used for supporting a lower chord member of the composite string truss and capable of adjusting the elevation of the lower chord member. The support is small in specification and size, simple in structure and convenient to machine, the installation efficiency of the assembled support can be effectively improved, the lower chord supporting mechanism used for supporting the lower chord of the composite string truss is supported throu