The invention discloses a steel bar bender for building. The steel bar bender comprises a machine frame, a conveying mechanism, a drive device, a workbench board and a supporting board, wherein the workbench board is arranged on the machine frame and the supporting board is arranged on the machine frame. A steel bar is arranged on the conveying mechanism. The drive device is installed on the supporting board. An output shaft of the drive device is provided with a shaft sleeve. A rotary shaft is connected to the upper portion of the shaft sleeve. An operation transverse beam is arranged on the rotary shaft. A first bending operation board and a second bending operation board are arranged on the workbench board. A circular space is formed between the first bending operation board and the second bending operation board. One end of the operation transverse beam stretches into the circular space and the portion, stretching into the circular space, of the operation transverse beam is provided with a fixing device for fixing the steel bar. The steel bar bender for building is simple in structure, convenient to use and install, easy to operate, capable of saving labor, low in cost, capable of conveniently conducting bending, high in bending accuracy and bending quality, capable of being conveniently maintained in the later period, large in application range, long in service life, safe and reliable.