China has a vast territory and abundant energy resources，while its distribution is not balanced. Electricity is the best way of energy consumption，and its stability of supply，economy，environmental protection play a key role in the stability and sustainable development of the whole society. The energy base of China is northward and westward trend，and the distance to eastern electricity load center is partly beyond the traditional EHV transmission distance. Based on the above objective，this paper overviews the relevant concepts and characteristics of ultra high voltage（UHV） after analyzing national conditions，then analyzes the value and significance for the energy security of our country，efficient and clean supply. Secondly，the article compares the development history of domestic and foreign countries，introduces the main engineering and related policies to support the development of UHV in China. Finally，the prospect of the development of UHV is discussed，and provided some points of views and suggestions for reference.