Steel beam and connecting structure for erecting concrete column on steel beam

The invention discloses a steel beam and a connecting structure for erecting a concrete column on the steel beam, and relates to the technical field of civil engineering, the steel beam comprises a steel beam body and a reinforcing assembly, the steel beam body comprises an upper flange, a lower flange and a web connecting the upper flange and the lower flange, and a cast-in-place area is arranged above the upper flange; the reinforcing assembly comprises an upper reinforcing piece and a lower reinforcing piece, the upper reinforcing piece is welded to the upper portion of the upper flange and extends into the cast-in-place area, and the lower reinforcing piece is arranged between the upper flange and the lower flange and located in a covering area of the cast-in-place area. The top end of the lower reinforcing piece is fixedly connected with the upper flange, and the bottom end of the lower reinforcing piece is fixedly connected with the lower flange. The steel beam is provided with the reinforcing assembly,