The circuit breaker has an arc extinguishing device, so the circuit breaker can be operated with load, not only can operate the load current but also operate the fault (short-circuit) current; and the disconnect switch does not have an arc extinguishing device, although the regulations stipulate that it can be operated at a load current less than in the case of 5A, it cannot be operated under load as a whole. The circuit breaker has a good packaging form, so simply observing the circuit breaker cannot intuitively determine whether it is in the closed or open position. The disconnect switch has a simple structure, and its operating status can be seen at a glance from the appearance, and there is an obvious disconnection point during maintenance. Circuit breakers are mostly operated by remote electric control, while disconnect switches are mostly operated manually on site