The invention provides a fast protection system, which comprises a two-out-of-three protection subsystem and a double protection subsystem, wherein the two-out-of-three protection subsystem comprises three sets of protection devices which are mutually independent; the double protection subsystem is embedded into the two-out-of-three protection subsystem; and the double protection subsystem and the two-out-of-three protection subsystem act and exit independently. The system comprehensively considers improvement of the performance and the cost of the protection system, so that a problem that a protection action is delayed or the load rate of the protection system is increased in case of a failure; the fast protection is configured for the major failure, so that the quickness, the reliability and the stability of the protection system are improved.