A pullback type disposable safety syringe includes a syringe body, a needle holder and a linkage assembly. The syringe body includes an injection end, a chamber and an opening； the needle holder has a receiving component and a snap component and both are located in the chamber, one end of the receiving component is a snap component, and the other end of the receiving component is located at the injection end to accommodate The needle assembly is movably disposed in the chamber through the opening, and includes a push rod and a piston disposed at one end of the push rod, and the hollow portion of the piston has a cross-sectional shape that matches the cross-sectional shape of the engaging member. When the chamber is filled with the medicament and an external force is applied to the push rod to drive the piston to move from the initial position to the engaged position, the medicament flows out of the needle, and the hollow portion engages with the engaging member, and then the push rod drives the piston to be reset from the engaged position. Return to the initial position so that the needle is inside the chamber.一種回拉型拋棄式安全針筒，其包括針筒本體、針頭座以及連動組件。針筒本體包括注射端、腔室以及開口；針頭座具有容置元件和卡合元件且其皆位於腔室內，容置元件的一端為卡合元件，容置元件的另一端位於注射端以容置針頭；連動組件透過開口活動地設置於腔室，並包括推桿和設置於推桿之一端的活塞，活塞之中空部截面形狀與卡合元件截面形狀契合。在腔室充滿藥劑時且施加外力於推桿而驅使活塞從初始位置移動至卡合位置時，藥劑從針頭流出，且中空部與卡合元件相接合，接著推桿帶動活塞從卡合位置復位回初始位置，從而使針頭位於腔室內。
