An injection syringe with a safety needle cap.It includes: a cylinder body and a set of connecting pipes.The diameter of the set of nozzles is smaller than that of the barrel.The set of nozzles is divided into one first section and one second section.The peripheral surface of the first section is formed with a plurality of wall surfaces；The second section is tubular.To connect an injection needle；One injection push rod,It can be reciprocally arranged on the barrel；A safety needle cover,It has a connecting part and a moving part.The connecting part has a certain position hole.The first section is arranged through the positioning hole and fixed with the hole wall of the positioning hole；The activity department is movably located in the connection department.And the movable part has a holding space and at least one stopper.At least one stopper is located in the holding space and provides the effect of the needle head stopper.一種具有安全針頭蓋之注射針筒，包含有：具有一筒身以及一套接管，該套接管之直徑係小於該筒身之直徑，該套接管區分一第一區段及一第二區段，該第一區段之周面形成有複數壁面；該第二區段呈圓管狀，用以連接一注射針頭；一注射推桿，可往復推移地設於該筒身；一安全針頭蓋，具有一連接部以及一活動部，該連接部具有一定位孔，該第一區段係穿置於該定位孔並與該定位孔之孔壁相固定；該活動部係可活動地設於連接部，且該活動部係具有一容置空間以及至少一限位件，該至少一限位件係位於該容置空間並提供該注射針頭限位效果。
