The invention relates to a circuit control system for a steel bar bundling machine. The circuit control system comprises a control center unit, a motor driving unit and a motor control unit. The system further comprises a spinning detection control unit and a torsion detection control unit. The control center unit transmits motor driving signals to the motor driving unit, the motor driving unit transmits the signals to the motor control unit to be used for controlling a motor to rotate, the spinning detection control unit detects and transmits spinning length signals to the control center unit, the torsion detection control unit detects and transmits torsion signals to the control center unit, and the control center unit performs processing according to the received torsion signals and the spinning length signals and then transits motor control signals to the motor driving unit. After the circuit control system is adopted, the automatic control is performed in the bundling process, the spinning length is adjusted as required, the spinning length is uniform, the waste is avoided; the torsion is proper, and the system can automatically adjust the proper torsion according to the intensity of the torsion.