The invention relates a large-current breaking device for an isolation switch and the isolation switch using the same. The breaking device comprises a movable-side breaking device and a static-side breaking device, wherein the static-side breaking device comprises a circuit breaker, the circuit breaker comprises an arc distinguishing chamber and an operation handle, the operation handle is provided with a switching-off position and a switching-on position which are used for driving a movable contact and a static contact of the arc distinguishing chamber into a switching-off state and a switching-on state during rotation around a rotational axis of the operation handle, the movable-side breaking device comprises a shift rod fixedly arranged on a corresponding conductive rod, the length of the shift rod extends along a horizontal direction, and a shift structure is arranged on the shift rod and used for shifting the operation handle to be rotated into the switching-on position from the switching-off position before the movable contact and the static contact of the isolation switch are switched on during switching-on of the conductive rod and shifting the operation handle to be rotated into the switching-off position from the switching-on position before the movable contact and the static contact of the isolation switch are switched off during switching-off of the conductive rod. With the adoption of the breaking device provided by the invention, the isolation switch has the ability of breaking large current.