Abstract: To improve the scanning uniformity and beam extraction efficiency, and to solve the problem of beam central deviation of DG-type electron accelerators, a scanning system has been developed, whose scanning coil and self-correcting coil are set in the same magnetic core. The system can scan along the X and Y axes and adjust the beam to the centre of the extraction window automatically. This paper introduces the parameter-selection basis of scanning magnet and scanning power-supply. We expound the design principle of the shaping circuit of the triangle wave current based square wave voltage. Moreover, the interlock signal from the scanning system is used to ensure the accelerators operation safety and stabilization. It is proved that the scanning system completely achieves the industrialization demand and the scanning uniformity meets the industrial irradiation requirements by the fact that the accelerator with the steady self-correcting scanning system is successfully used in practice.