A peg-count type syringe comprises a syringe needle set, an injection barrel set, an injection plunger set and a peg-count ring, wherein the syringe needle set is used for connecting with pharmaceutical vials, the injection barrel set is sleeved on the outside of the pharmaceutical vial, and can be detachably connected to the syringe needle set, the injection plunger set is disposed within the injection barrel set through the sleeved connection of the plunger body and the peg-count ring. Each time after the peg-count syringe is filled with medicine vial and injected, the syringe needle set together with the pharmaceutical vial can be removed and abandoned, and combination of the injection barrel set, injection plunger set and peg-count ring is reusable. Because of the thread grooves between the peg-count ring and the plunger body being structurally matches with the interference thread bumps, as well as the snap combination of the ratchet groove of peg-count ring and the injection barrel set, each time the injection plunger set is pulled back when detaching the pharmaceutical vial, a re-use frequency is automatically counted, and when it reaches the preset use frequency, the peg-count ring can no longer rotate, and the injection plunger set cannot be pulled back for use, thereby avoiding over reuse of the peg-count type syringe to ensure use safety.一種計次式注射器,係包含針頭套組、注射套筒組、注射推桿組與計次環,針頭套組用以組接藥劑瓶,注射套筒組套設於藥劑瓶外側,且可拆組地組接針頭套組,注射推桿組以其桿體套接計次環而設置於注射套筒組內,該計次式注射器每次裝填藥劑瓶注射後,可將針頭套組連同藥劑瓶拆除拋棄,注射套筒組、注射推桿組與計次環之組合則能重複使用,並藉計次環與桿體間之螺紋槽與干涉螺紋凸塊匹配構造,以及計次環之棘齒槽與注射套筒組中之彈扣組合,使每次拆裝藥劑瓶而向後拉動注射推桿組時,自動計數重複使用次數,到達預設的使用次數時,計次環無法再旋轉,注射推桿組無法後拉使用,避免該計次式注射器過度重複使用,確保使用安全性。10‧‧‧針頭套組11‧‧‧藥瓶套蓋111‧‧‧組合端部112‧‧‧卡合端部1121‧‧‧卡合槽1122‧‧‧導斜面12‧‧‧針頭套121‧‧‧套體122‧‧‧針頭13‧‧‧安全護套20‧‧‧注射套筒組21‧‧‧卡夾套筒211‧‧‧卡接端部2111‧‧‧卡合勾212‧‧‧組接端部2121‧‧‧環卡槽22‧‧‧剝蓋套筒221‧‧‧抵接端部222‧‧‧連接端部223‧‧‧長槽23‧‧‧注射輔助套筒231‧‧‧套筒本體232‧‧‧軸管部2326‧‧‧連接塊233‧‧‧輔助翼片234‧‧‧觀視窗30‧‧‧注射推桿組31‧‧‧桿體311‧‧‧桿身3111‧‧‧干涉螺紋凸塊312‧‧‧活塞推塊313‧‧‧停轉控制端部314‧‧‧端頭315‧‧‧停轉肋條316‧‧‧卡接凹槽317‧‧‧活
