The invention relates to a safe syringe comprising a barrel, a needle seat and a plunger, wherein the needle seat has a hook rod, a linkage deformation portion and a barrel clamping portion； and the plunger has a rod body, and a hook insertion hole which can be sleeved with the hook rod of the needle seat and compress the linkage deformation portion for elastic deformation such that the barrel clamping portion of the needle seat is not clamped into the seat clamping slot of the barrel, and the hook insertion hole can hook the hook rod of the needle seat to move the needle seat. The safe syringe can allow stable positioning and quick pullback of the needle seat and effectively reduce liquid medicine residue.
