A needle protecting module of an injection device in connecting with a syringe has a needle base, a needle body a tube module, a mounting tube, an elastic unit, and a stopping unit. The syringe has a tube body and an axis. The needle body transfixes the needle base and communicates with the tube body for medication injection. The needle base is removably engaged with the tube body and bearing the needle protecting module is transfixed by the needle body. The tube module is mounted around the needle base and has an annular space. The mounting tube is movably inserted into the annular space. The elastic unit is mounted in the annular space and abuts both the mounting tube and the needle base bilaterally. The stopping unit is moveably mounted in the annular space and is selectively engaged with the mounting tube.本發明提供一種注射針器的防護裝置,包含與一注射針器連結且供一針體穿出的一針座、與該針座連接的一套管組、可位移的穿置在該套管組內的一活動套管、穿置在該套管組內且作用於該活動套管的一彈性元件,及阻擋該活動套管只能在該套管組內位移的一擋止件。注射過程中,該活動套管可於脫離該擋止件後,藉該彈性元件的彈性作用力朝反向於該針座的方向位移,至其二卡止面分別受阻於該套管組的二階面後,完全包覆該針體且無法沿該軸線方向移動。藉此,利用前述階面與卡止面,及擋止件間特殊的位置關係,使本發明在注射完成後,自動隱藏該針體,不但能夠簡化組件與構造,且能夠提升醫療臨床注射操作的順暢性、安全性與實用性。2‧‧‧注射針器20‧‧‧管件22‧‧‧針座220‧‧‧環緣221‧‧‧對合部222‧‧‧對合部223‧‧‧架橋224‧‧‧擋止面225‧‧‧階面23‧‧‧針體3‧‧‧套管組30‧‧‧環槽31‧‧‧內套管312‧‧‧第一環面313‧‧‧階面314‧‧‧穿口315‧‧‧肋條316‧‧‧卡合部318‧‧‧平面端緣32‧‧‧外套管322‧‧‧第二環面323‧‧‧階面4‧‧‧活動套管41‧‧‧卡止面42‧‧‧卡止面43‧‧‧凸部44‧‧‧第一凹部45‧‧‧第一凹部46‧‧‧第二凹部5‧‧‧彈性元件6‧‧‧擋止件61‧‧‧斜面62‧‧‧限止面7‧‧‧端蓋71‧‧‧穿孔
