The present application discloses a safety injection needle, comprising a needle base (1) provided on the end potion thereof with a needle tube (2), characterized in that the needle base (1) being provided at one side with a safety sheath (3), an elastic telescopic plate (4) being provided at the junction between the safety sheath (3) and the needle base (1), the safety sheath 3 rotatable about the elastic telescopic plate (4) which can be seen as a central supporting point, the safety sheath (3) having a hollow cavity which is provided therein in sequence with a sheath safety hook (301) which is located adjacently to the elastic telescopic plate (4) and a needle tube safety hook (302), the needle base (1) being provided with a needle base safety hook (101) cooperating with the sheath safety hook (301). The safety protection mechanism is integral with the needle base and the multiple-segment engagement mechanism, in particular reversed double hook mechanism ensure that the safety protection mechanism cannot separate from the needle tube after they engage with each other so that a safety factor of the injection needle is improved efficiently and the whole design of the product is reasonable and the conceivability is out of box and the operation of it is convenient and efficient. Compared to the conventional product, the present invention possesses prominent substantive feature and notable development.
