It is a historical mission for researchers in the field of power switching to reduce or replace the usage of SF_6 gas,which is a contribution to the global climate change. An effective way to reduce or replace the usage of SF_6 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,SF_6 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.