Disclosed is a bending device for metal bars. The bending device comprises a hollow base, a hydraulic cylinder, two circular shafts and a pressure head, two ends of the base are open, the hydraulic cylinder is arranged on the base, the extension end of the hydraulic cylinder extends to the inside of the base, the pressure head is connected with the extension end of the hydraulic cylinder, and the two circular shafts are arranged in the base and respectively located on two sides of the pressure head. The bending device has the advantages that the metal bars are bent without manpower, labor intensity of workers is lowered, besides, the bending process of the metal bars is easy to control, and quality of finished products is high.