Universal adjustable connecting piece for multi-layer combined curtain wall system

The utility model discloses a universal adjustable connecting piece for a multi-layer combined curtain wall system, which comprises an I-shaped adapting piece and a universal butt joint which are used for being connected with a stand column, and further comprises a bolt group which is used for connecting the I-shaped adapting piece and the universal butt joint and enables the universal butt joint to rotate relative to the I-shaped adapting piece, the universal butt joint comprises a base, the base is connected with a cover plate through stainless steel bolts, cavities are formed in the inward side and the outward side of the cover plate and used for installing a perforated aluminum veneer or an embedded lamp, and a decorative buckle cover is arranged on the cavity in the outward side of the cover plate in a buckled mode. Notches in the left side and the right side of the cover plate are provided with buckle plates and bent sealing plates to form sealing openings. The multi-layer combined curtain wall system c