A retractable self-destructing safety syringe with pre-attached needle including a barrel, an inner needle base disposed in a barrel neck at an end of the barrel body, and an elastic engagement mechanism formed between the barrel neck and the inner needle base is provided. An asymmetric elastic locking member having an elastic function is disposed at the end of the plunger, with which a sleeve-type retractable locking member on the needle base can be interlocked by the elastic function. After being retracted into the barrel body, the needle base together with the needle will be forced to deflect to one side under an asymmetric force, and the needle therefore will be forced to incline in a direction nearly a 45 degree angle toward to one side of the inner wall of the barrel and is blocked by the barrel neck, so that the needle and the needle base could not be pushed out the barrel neck again and self-destruction of the syringe is truly achieved. The asymmetric elastic locking member is a plastic hook which is formed with the plunger body by one-time molding process.
