The invention discloses a needle seat pull-back type safe self-locking self-destruction syringe. The needle seat pull-back type safe self-locking self-destruction syringe comprises a syringe barrel, a core bar is arranged inside the syringe barrel, and a needle seat is arranged inside the barrel neck at the end portion of the syringe barrel a seal ring is sleeved outside the outer wall of the needle seat, a needle replaceable part is formed on the upper portion of the needle seat, and an elastic support snapper is arranged inside the lower cavity of the needle seat a locking engaging mechanism which is matched with the end portion of the core bar is arranged inside the elastic support snapper and is elastic an elastic support limit mechanism which is matched with the inner wall of the internal cavity of the syringe barrel is formed outside the elastic support snapper an engaging part which is matched with the locking engaging mechanism is formed at the end portion of the core bar. The needle seat pull-back type safe self-locking self-destruction syringe has the advantages that the needle seat and a sleeve can be directly assembled in an embedded mode in any circumferential direction clamping claws can provide a large needle return resistance in a forward direction and meanwhile reduce the pull-back resistance in a reverse direction a self-locking structure of the core bar and the sleeve is simple in structure and easy to manufacture but achieves a self-locking function.
