Steel bar binding device for building construction

The utility model discloses a steel bar binding device for building construction, which comprises a machine body, a shaft body is arranged in the machine body, a wire coil is sleeved on the surface of the shaft body, a first bevel gear is arranged on the surface of the shaft body, and the first bevel gear is meshed with a second bevel gear. According to the automatic pay-off device, the driving motor is started, the driving motor drives the rotating shaft to rotate, then the third bevel gear and the second bevel gear are driven, the second bevel gear is connected with the first bevel gear in a meshed mode, the shaft body and the wire coil are driven to rotate, and therefore the purpose of automatic pay-off is achieved; and a fourth bevel gear drives a conveying wheel to rotate, then the conveying wheel conveys the binding wire, the problem that a wire coil cannot pay off due to insufficient friction force is solved, the practicability of the device is greatly improved, and due to the arrangement of a rubber s