The utility model relates to the technical field of isolation switch sealing. The utility model relates to a sealing assembly, in particular to a sealing assembly between a PR type knife switch mechanism box and a rotating shaft. The sealing assembly is characterized in that the sealing assembly is composed of a main protection adjusting ring, a main locking pin, a secondary locking pin, a lockingpull rod and an auxiliary protection adjusting ring; the main protection adjusting ring is arranged to be an open annular plate. Connecting rings parallel to the axis of the annular plate are arranged at the two ends of the annular plate respectively; the connecting rings are respectively connected with the end parts of the annular plates; a primary locking pin and a secondary locking pin are respectively arranged in the connecting ring; a threaded hole is formed in the side surface of the main locking pin; a connecting hole is formed in the side surface of the secondary locking pin; one endof the locking pull rod is rotationally connected with the secondary locking pin, the other end of the locking pull rod is connected with the threaded hole through threads, the auxiliary protection adjusting ring is arranged on the inner side face of the annular plate, the auxiliary protection adjusting ring is arranged to be an arc-shaped plate, and the mechanism box has the advantages of being simple in structure, improving the waterproof function, preventing elements in the mechanism box from being damped, oxidized and damaged and the like.