A mobile high voltage generating device for providing power to an X-ray apparatus, includes a power supply unit including a battery and an isolated DC-DC converter electrically coupled with the battery； an energy storage unit, electrically coupled to the isolated DC-DC converter of the power supply d a voltage conversion unit coupled between the energy storage unit and a radiation source of the X-ray apparatus； wherein the isolated DC-DC converter includes: a first inverter circuit coupled to a battery, a first rectifier circuit coupled to the energy storage unit, a first transformer including a primary winding and a secondary winding. The primary winding is coupled to the first inverter circuit and the secondary winding is coupled to the first rectifier circuit.
