It is stressed in the outline of The Twelfth five-year plan of State Grid Company of China（SGCC in short）to expand further the scale of transmitting electric power from the west to the east in China and to develop transmission technology with ultra high voltage

high power

high efficient and long distance.Under the opportunity of SGCC in speeding up UHV grid and for the new requirement of market to the reactive compensation

the new generation of assembling reactive compensation device is studied and developed by us.In this paper

the research and design on 66kV 20Mvar assembling capacitor with high voltage and power are introduced in detail.