VK12-12M series indoor permanent magnet high voltage vacuum circuit breaker (hereinafter referred to as the circuit breaker), a permanent magnet vacuum circuit breaker with unique technology, is applicable to the distribution system with three-phase AC 50Hz and rated voltage of 12kV. The circuit breaker adopts the design scheme of permanent magnet operating mechanism and three-phase coaxial. It is assembled into a handcart with a standard chassis car. When it is used, it does not need to make any change to the matching size of the switch cabinet, and can be directly used for kyn28 switch cabinet; It can also be installed in other indoor compartments as a separate switching unit.