The invention relates to a connecting tooling used for a single column and composite cylinder combined foundation. A single column is inserted into a composite cylinder. The top end of the composite cylinder is provided with a fixed top cover plate. The connecting tooling comprises a connecting main plate and a plurality of stiffening webs fixedly connected to the lower plate surface of the connecting main plate. A connecting through hole adapting to the single column is arranged on the plate surface of the connecting main plate. The multiple stiffening webs are arranged around the connectingthrough hole, and the upper lateral sides of the stiffening webs are fixedly connected to the lower plate surface of the connecting main plate. The connecting main plate is connected to the single column in a sleeving mode, and the inner wall of the connecting through hole is welded to the single column. The inner lateral sides, facing the connecting through hole, of the stiffening webs are attached and welded to the columnar surface of the single column, and the lower lateral sides of the stiffening webs are attached and welded to the top cover plate. The connecting tooling related by the invention is simple in structure and convenient to mount and operate, the single column and the composite cylinder are stably connected and form an integrated structure, and big bending moment transmitted from the single column is transmitted to the whole composite cylindrical surface.