The invention discloses a curtain wall connecting assembly. The curtain wall connecting assembly is used for mounting stone face plates on a main keel and comprises an upper hanging piece, a crossbeamand a lower hanging piece; the upper hanging piece and the lower hanging piece are detachably connected with the crossbeam, and the crossbeam is detachably mounted on the main keel; the upper hangingpiece is detachably connected with the lower end of one of the stone face plates, and the lower hanging piece is detachably connected with the upper end of another stone face plate adjacent to the lower portion of the stone face plate; and the distance d from the connection point of the upper hanging piece and one of the stone face plates to the surface of the main keel is smaller than the distance D from the connection point of the lower hanging piece and another stone face plate to the surface of the main keel. Thus, the stone face plates are mounted on the main keel by a certain slant angle through the connecting assembly, the upper end gap of one of the stone face plates is larger than the lower end gap of the adjacent upper-portion stone face plate, thus rainwater can be guided intothe back face of stone and falls to the ground along the space between the main keel and the stone face plates, and face plate pollution and sealant aging caused by scouring of the rainwater on the stone face plates and sealants are avoided.