The invention relates to a vacuum switch and a circuit breaker. The vacuum switch comprises more than two enclosed poles and an intermediate conductive member. Each enclosed pole is provided with an outgoing end conductive member and an incoming end conductive member. The outgoing end conductive member of each enclosed pole and the incoming end conductive member of the adjacent enclosed pole are connected in series in turn through the intermediate conductive member. The original one vacuum fracture is increased to multiple vacuum fractures through series connection of multiple enclosed poles and the fracture distance is multiple times of the original number so that the reignition phenomenon in the breaking process can be greatly reduced and even eliminated, the overvoltage phenomenon alsodisappears and thus the service life of the switching capacitor bank can be enhanced.