The utility model provides an isolated circuit breaker, including moving contact and static contact, this isolated circuit breaker be servo drive formula circuit breaker, and it is still including being used for driving the operating mechanism of moving contact motion with opening range different between realization and the static contact, the operating mechanism is in the different servo motor that set for the position including the control moving contact, the moving contact has a three settlement position, and first position is for being in closure state combined floodgate position down, and a second position is for being in the separating brake position under the switching -off state, and a third position is the isolation position at the separation state under, opening range when the moving contact is in isolation position is greater than its opening range when the separating brake position. Through using this servo drive isolated circuit breaker, can solve the problem that leads to isolator, divide -shut brake function to coordinate owing to adopt fixed opening range mode between traditional isolated circuit breaker's sound contact.