The invention discloses a permanent
magnet vacuum
circuit breaker which comprises a circuit breaking unit and a bearing device used for installing the circuit breaking unit, the circuit breaking unit comprises a permanent
magnet mechanism, an insulating part, a connecting
assembly, a
contact pressure spring, a conducting strip, a
vacuum arc-extinguishing chamber, a switch static contact and a
synchronizing assembly, and the permanent
magnet mechanism comprises a movable core iron pull rod and a dustproof cover used for protecting the movable core iron pull rod. The connecting
assembly comprises a first connecting rod, the movable core iron pull rod and the first connecting rod are each provided with a milled flat structure, the
synchronizing assembly comprises a
synchronizing shaft, a transmission pin, a synchronizing base and a synchronizing contact arm, and the synchronizing base guides the synchronizing shaft and the transmission pin. According to the permanent magnet vacuum
circuit breaker, a direct driving design is adopted, many transmission links are reduced, the
energy consumption is reduced, and the transmission efficiency is ensured to the maximum extent. The permanent magnet vacuum
circuit breaker disclosed by the invention is designed to be integrally miniaturized, so that the reliability of an on-off circuit of a gas insulated
switchgear can be improved, and shorter on-
off time can be obtained.