The invention discloses a high-
voltage generator used for an X-
ray machine and a control method thereof. The high-
voltage generator comprises a rectifying and wave-filtering and soft-start unit connected with a power supply, a
control power supply, and a
voltage rising and rectifying unit in a high-voltage
oil tank. The high-
voltage generator is characterized in that the rectifying and wave-filtering and soft-start unit is connected with a
power factor correction unit, is connected with the positive pole of an X-
ray tube in the high-voltage
oil tank through a high-
voltage inverter and the voltage rising and rectifying unit, and is connected with the negative pole of the X-
ray tube through a filament
inverter and a filament converting circuit; a sampling circuit connected with a central
control unit is arranged inside the high-voltage
oil tank; and the central
control unit is respectively connected with the high-
voltage inverter, the filament
inverter and a host computer. Compared with the prior art, the high-
voltage generator has the advantages that the high-
voltage generator adopts a series-
parallel resonance technique to realize the zero-voltage opening of a switch tube, and thus the
switching frequency can be improved to 100 kHz; the problems of
high voltage insulation and protection caused by extracting a
high voltage wire externally connected with an X-ray tube from the high-voltage oil tank are avoided because that the X-ray tube is integrated inside the high-voltage oil tank.