A safety syringe structure includes a combined structure of a syringe barrel, a needle retreater, a needle, and a plunger. The needle retreater and the plunger are slidably received in the syringe barrel. The needle retreater is arranged adjacent to the front end of the syringe barrel. The needle is coupled to the needle retreater. The plunger has an end extended to form a sharp tip and is provided with a plug facing the needle retreater. The sharp tip extends outside the plug in a direction toward the needle retreater. The sharp tip is movable with the plunger toward the front end of the syringe barrel to pierce into and couple with the through hole of the needle retreater and the sharp tip is movable with the plunger toward the rear end of the syringe barrel to drive, through the needle retreater, the needle into the channel.