The present invention provides a high-voltage direct current power supply. The high-voltage direct current power supply comprises at least two cascaded boost rectification modules, one input end of each boost rectification module is configured to connect with an alternating current power grid, one output end of each boost rectification module is configured to connect with a load to provide a direct current voltage after boosting to the load, each boost rectification module comprises one power frequency rectification unit and one inversion boost unit, each power frequency rectification unit isconfigured for rectification, each inversion boost unit is configured to perform inversion boost of the voltage after rectification by employing the rectification unit, and finally, the direct currentvoltage after boosting is filtered by employing a high-voltage filtering module to obtain a pure high-voltage direct current power supply on the load. The high-voltage direct current power supply replaces a high-voltage direct current generation mode with a multi-stage rectification module cascade mode so as to reduce boosting change, reduce high-voltage power ripples, and the high-voltage filtering module is configured to further filter high-frequency ripples to ensure safe and reliable operation of the system.