A safety syringe has a barrel, a pushing element, a retracting element, and a needle group. The barrel is hollow and has a needle-group mounting end, an operating grip end, and a barrel lumen. The pushing element is retractably mounted in the barrel lumen and has a pushrod chamber. The retracting element is airtightly and slidably mounted in the pushrod chamber. The needle group is connected to the needle-group mounting end of the barrel. The present invention can pull the retracting element to move relative to the pushing element to form a low pressure condition in the pushrod chamber as a vacuum status. After the injection, a vacuum attraction force in the pushrod chamber can retract the used needle group into the pushrod chamber for safe use of the safety syringe.本發明係關於一種安全注射器,主要包括有一筒體、一推送件、一回抽件及一針頭組;該筒體係呈中空圓筒體並分別具有一針頭組安裝端及一操作握持端,並於該筒體內部形成一筒腔,該推送件係可抽拔地設置於該筒腔內,並於該推送件的內部形成一推桿腔,該回抽件係可氣密滑移地設置於該推桿腔,該針頭組係對應設置於該針頭組安裝端;本發明係能夠透過該回抽件使該推送件的內部形成真空狀態,並在注射完成後,藉由該推送件內部的真空吸力將已使用後的廢棄針頭組回抽入該推桿腔內,以達到安全處置該注射器的目的。10‧‧‧筒體11‧‧‧針頭組安裝端110‧‧‧針體伸出孔111‧‧‧減阻間距112‧‧‧抵靠階緣113‧‧‧肋條114‧‧‧針座護持孔12‧‧‧操作握持端120‧‧‧手握部1201‧‧‧標籤孔121‧‧‧進入端122‧‧‧凸環13‧‧‧筒腔130‧‧‧卡制凸環131‧‧‧針座定位段132‧‧‧活動段20‧‧‧推送件21‧‧‧活動推桿210‧‧‧推桿腔211‧‧‧第一卡環212‧‧‧外環緣213‧‧‧環套部214‧‧‧卡合緣215‧‧‧內環216‧‧‧藥劑推送端217‧‧‧操作端218‧‧‧第二卡環22‧‧‧外氣密擋塞221‧‧‧塞合孔222‧‧‧環溝23‧‧‧內氣密擋塞231‧‧‧凸出部2311‧‧‧凹環槽232‧‧‧塞合部2321‧‧‧環槽233‧‧‧針座連結部234‧‧‧拔塞槽24‧‧‧端蓋241‧‧‧蓋身242‧‧‧蓋合槽243‧‧‧蓋底244‧‧‧護持管2440‧‧‧卡止緣30‧‧‧回抽件31‧‧‧拉桿311‧‧‧卡固端3110‧‧‧卡固凸環3111‧‧‧卡制環緣312‧‧‧握持端3120‧‧‧凹槽313‧‧‧凹陷缺口32‧‧‧氣密塞套321‧‧‧卡合部322‧‧‧卡合槽3220‧‧‧卡固環緣323‧‧‧環卡槽40‧‧‧針頭組41‧‧‧針體42‧‧‧針座421‧‧‧針體固定孔422‧‧‧嵌合部4220‧‧‧剖槽423‧‧‧浮凸緣43‧‧‧針座固定環431‧‧‧抵靠面432‧‧‧卡制環槽433‧‧‧針座氣密固定孔50‧‧‧針蓋A‧‧‧安全注射器
