A safety syringe with retractile rotation is disclosed. The plunger is capable of rapidly embedding with and positioning at the needle set, the next step of the retractile movement to retract the needle is easily processed by a user, and the needle set is firmly assembled and positioned at the open end of the barrel so as to not easily result an unpredictable phenomenon, such as deteriorating the suitability between the needle set and the barrel to result the needle set indentation and leakage when injecting from a sharp raise in temperatures, or overtightening the needle set and the barrel to result the needle and the needle set incapable of retracting in the barrel from the sharp fall of temperature. Furthermore, this invention is capable of achieving one hand operation with safety, improving environmental protection quantity, and easy use for retracting the needle.
