A nail head assembly comprises: a nail cartridge support (1), a nail cartridge (2) being detachably disposed on the nail cartridge support (1) a nail anvil that can be pivotally closed relative to the nail cartridge (2) a triggering block (3) that is movably disposed in the nail cartridge (2), an unlocking component (32) being provided in the triggering block (3) a cutter (5), the cutter (5) being capable of moving at least between a first position and a second position relative to the nail cartridge support (1) along the longitudinal direction thereof, a cutter pushing rod (4) being disposed on a near end of the cutter (5), a cutting edge being disposed on a far end (52) of the cutter (5), and the cutter (5) pushing the triggering block (3) to move with the push of the cutter pushing rod (4) a safety mechanism, the safety mechanism comprising a safety block (61), the safety block (61) being disposed in the nail cartridge support (1) and being capable of moving between a third position and a fourth position relative to the nail cartridge support (1) along the transverse direction of the nail cartridge support (1) an elastic component (62) that is disposed between the nail cartridge support (1) and the safety block (61), the elastic component (62) driving the safety block (61) to move from the third position to the fourth position. The nail head assembly is capable of effectively preventing triggering again in a case in which a triggered nail cartridge is not replaced.Linvention concerne un système de tête de clou comprenant: un support de cartouche de clou (1), une cartouche de clou (2) étant disposée de manière amovible sur le support de cartouche de clou (1) une enclume de clou qui peut être fermée de façon pivotante par rapport à la cartouche de clou (2) un bloc de déclenchement (3) qui est disposé de manière à pouvoir se déplacer dans la cartouche de clou (2), un composant de déverrouillage (32) étant prévu dans le bloc de déclenchement (3) un dispositif de cou
