Abstract: The demagnetization current is applied to pulse transformer to improve the utilization ratio of the magnetic core. A pulse reset circuit working at low voltage was studied to generate a pulse current contrary to the main discharge current. The effectiveness of magnetic core reset under different capacitances and charging voltages was studied. The result implied that the power saved in the capacitor had a positive correlation with the effectiveness of reset circuit. Considering the output targets, a larger capacitance with a lower working voltage was selected. The output characteristics of the pulse transformer with a toroidal magnetic core emphasized the necessity of reset circuit. Experiments showed that the reset circuit could run steadily for a long time under 50 Hz repetition rate.