Abstract: A safety syringe includes a plunger for moving a rubber stopper in a barrel to force the medicine out of a needle assembly into the patient's body that has a connector at the front side of a shank thereof to hold a metal hook for hooking the needle assembly so that the needle assembly can be pulled backwards and received inside the barrel after the service of the safety syringe. The invention relates also automatic fabrication of the plunger through a syringe plunger processing system that comprises a metal hook dispenser for dispensing metal hooks, a connector dispenser for dispensing connectors, a high-frequency heat-sealing apparatus for bonding each metal hook to one respective connector, and an injection molding apparatus for molding a shank on each combination of metal hook and connector.