A -35 kV/2.8 MW/1000s high-voltage power supply (HVPS) for HT-7 superconducting tokamak has been built successfully. The HVPS is scheduled to run on a 2.45 GHz/1 MW lower hybrid current drive (LHCD) [1] system of HT-7 superconducting tokamak before the set-up of HT-7 superconducting tokamak in 2003. The HVPS has a series of advantages such as good steady and dynamic response, logical computer program controlling the HVPS without any fault, operational panel and experimental board for data acquisition, which both are grounded distinctively in a normative way to protect the main body of HVPS along with its attached equipments from dangers. Electric power cables and other control cables are disposed reasonably, to prevent signals from magnetic interference and ensure the precision of signal transfer.This paper involves the experiment and operation of a 35 kV/2.8 MW/1000 s HVPS [2] for 2.45 GHz/1 MW LHCD system. The reliability and feasibility of the HVPS has been demonstrated in comparison with experimental A -35 kV / 2.8 MW / 1000s high-voltage power supply (HVPS) for HT-7 superconducting tokamak has been successfully built. The HVPS is scheduled to run on a 2.45 GHz / 1 MW lower hybrid current drive ] system of HT-7 superconducting tokamak before the set-up of HT-7 superconducting tokamak in 2003. The HVPS has a series of advantages such as good steady and dynamic response, logical computer program controlling the HVPS without any fault, operational panel and experimental board for data acquisition, which both grounded distinctively in a normative way to protect the main body of HVs along with its attached equipments from dangers. Electric power cables and other control cables are reasonably, to prevent signals from magnetic interference and ensure the precision of signal transfer. This paper involves the experiment and operation of a 35 kV / 2.8 MW / 1000 s HVPS [2] for 2.45 GHz / 1 MW LHCD system. The reliability and feasibility of the HVPS has been demonstrated in compariso n with experimental