It is a historical mission for researchers in the field of power switching to reduce or replace the usage of SF6 gas

which is a contribution to the global climate change. An effective way to reduce or replace the usage of SF6 gas in the field of power switching is to develop high voltage level switching technology in vacuum. First

this paper reviewed four key technologies for high voltage level switching in vacuum

which include high voltage vacuum insulation

high current interruption

operating mechanism and control technology of displacement curve

and enhancement of nominal rated current. Second

it introduced the application and operation of high voltage level vacuum switchgear in China and in the world. Third

this review includes the prospects of high voltage level vacuum switching technology. It prospected the development of high voltage vacuum breaker technology from eight aspects

which included vacuum interrupter with ceramic envelope and multi-floating shields

enhancement of nominal rated current

SF6 alternative gas for external vacuum interrupter insulation

new operating mechanism

gas insulated "vacuum"switchgear

liquid nitrogen insulated "superconducting"switchgear

new DC circuit breakers and ultra high voltage vacuum circuit breakers.