Key and key connecting assembly thereof

The invention discloses a key and a key connecting assembly thereof. The key connecting assembly comprises a first bracket, at least one first rotating shaft and a bottom plate, the first support comprises a first bottom plate section, at least one first rotating shaft is located on the first bottom plate section, the at least one first rotating shaft is provided with a first arc part and a first conical part which are arranged oppositely, and the first arc part is higher than the first conical part. The bottom plate comprises a first holding part and a second holding part which are jointly connected with the first rotating shaft of the first support, and the first holding part and the second holding part are staggered in the axial direction and the radial direction of the first rotating shaft and located on the two opposite sides of the first rotating shaft respectively. The second holding part is provided with a second clamping hook adjacent to a first arc part of the first rotating shaft, the first holding