The application discloses a self recovery method and a self recovery device of a boundary security and protection system. The method comprises the following steps of: detecting multiple paired detectors in the boundary security and protection system; if a fault detector exists in the paired detectors, pairing a target detector with an adjacent detector, and transceiving signals, wherein the target detector is a detector paired with the fault detector. If the detector arranged in the boundary security and protection system has a fault, and security and protection blanks, a seamless microwave protection zone is reconstructed by virtue of the self recovery method of the boundary security and protection system; by virtue of reconstructing the seamless microwave protection zone, security and protection are realized, occurrence of a monitoring blind zone is avoided, the time consumption and labor consumption for manual maintenance are reduced, and the security and protection precision of the boundary security and protection system is improved.