This paper presents a PWM signal correction technique to prevent magnetic saturation of high-voltage transformer under wide range load in high-voltage X-ray generators. A high-frequency PWM inverter provides asymmetric voltage caused by uneven delays of control ICs on its drive and control circuits, and power switching devices. The magnetic core of the high-voltage transformer connected to the high-frequency PWM inverter would be in magnetically asymmetric condition, and finally fallen into the magnetic saturation. The PWM signal correction technique which controls the average inverter output current to zero is proposed and discussed. The effectiveness of the PWM signal correction are confirmed based on measured magnetized current of the high-voltage transformer and the inverter output current waveforms.