A medical injection device, comprising: a housing having a first end cover and a second end cover provided at two ends thereof, respectively a dial threaded rod, which is in threaded connected to the first end cover and, a piston rod, which is used for expelling a dose, an upper end of the piston rod being connected to the dial threaded rod through a driving mechanism while a lower end thereof is in threaded connected to the second end cover. It further comprises a dosage adjustment mechanism, which is arranged between the dial threaded rod and the housing and used for driving the dial threaded rod to move in an axial direction of the housing.本創作公開了一種醫用注射裝置,包括:殼體,其兩端部分別設置有第一端蓋、第二端蓋;刻度螺桿,與第一端蓋螺紋連接;活塞桿,用於擠出藥劑,活塞桿的上端與刻度螺桿通過驅動機構連接,活塞桿的下端與第二端蓋螺紋連接;醫用注射裝置還包括:設置於刻度螺桿與殼體之間的劑量調節機構,用於帶動刻度螺桿沿殼體軸向移動;當刻度螺桿螺旋上升時,驅動機構至少部分跟隨刻度螺桿直線上升;當刻度螺桿在螺旋下降時,驅動機構至少部分跟隨刻度螺桿作螺旋下降運動,並驅動活塞桿同步螺旋下降運動。與現有技術相比,本創作的醫藥注射裝置具有結構簡單、調節方便、調節精細度高、安全係數高、操作方便,製作成本低等優點。2‧‧‧棘輪2a‧‧‧觸發開關按鈕9‧‧‧刻度螺桿10‧‧‧殼體13‧‧‧第一端蓋19‧‧‧第二端蓋21‧‧‧活塞桿34‧‧‧活塞41‧‧‧凸點43‧‧‧拉簧71‧‧‧驅動件72‧‧‧壓縮彈簧
