It has been learned recently that the "Research on Improving the Reliability of UHV Transformer" by the State Grid Corporation of China led by the China Electric Power Research Institute successfully passed the inspection of the Company. The research results of the project will effectively improve the operational reliability and stability of the UHVDC transformer Structural Design of DC Voltage Divider for Improved UHV Converter Station. The long-term operating stability of UHV GIS electronic transformers has an important impact on the safe and reliable operation of UHV projects. The research on the reliability of UHV GIS electronic transformers is still in a groping phase. The EVTs and ECTs developed by the project achieve prioritization, mutual backup and "on duty" status conversion and status assessment and maintenance functions, which solves the reliability, service life and operation and maintenance issues of UHV GIS electronic transformers . At present, DC ± 500kV and ± 800kV DC voltage dividers operated by DC converter stations in China mainly use imported products, dirty conditions or light rain. The flashover under heavy fog conditions has troubled the safe operation of converter stations. DC voltage divider External flash often appear, internal discharge phenomenon also occurs from time to time. In order to promote the technological upgrading of UHV converter station equipment in China, the project also conducted an in-depth study on the internal structure design of the UHV DC voltage divider and completed the optimization of the internal structure of the UHV DC voltage divider. The project achievements have improved the reliability of UHV and UHVDC equipment and ensured the stable operation and construction of UHV. It has significant economic and social benefits.