It is automatically stopped liquid feed device when a kind of drop syringe lacks liquid,Including reservoir； Contact pin,It is connected to reservoir top and is arranged upward； Conical sleeve,It is made by soft materials,For structure wide at the top and narrow at the bottom,And it is connected to the bottom end of reservoir； And sphere,It is arranged in conical sleeve,At least big what conical sleeve bottom diameter of sphere diameter,And small what conical sleeve top end diameter,The small what water of sphere specific gravity； Thereby,Directly it is set in the bottom end of reservoir in the way of adding using conical sleeve,Without in addition processing,Reduction production cost is used,And be directly added on existing product,Using,Assembling and convenient disassembly； FurthermoreUsing the specific gravity of the small what water of diameter and sphere of the corresponding conical sleeve of sphere,Circulation status and blocking state are automatically formed,With effect convenient to use.一種點滴注射器缺液時之自動停止供液裝置，包括儲液槽；插針，與儲液槽頂端連通並朝上設置；錐形套筒，由軟性材質所製，為上寬下窄的結構，並與儲液槽的底端連通；及球體，設置在錐形套筒內，球體直徑至少大於錐形套筒底端直徑，且小於錐形套筒頂端直徑，球體比重小於水；藉此，利用錐形套筒以外加方式直接套設在儲液槽的底端，而無需另外加工，藉以降低生產成本，而且直接外加在已有的產品上，使用、組裝及拆卸方便；再者，利用球體相對應錐形套筒的直徑大小以及球體小於水的比重，自動形成流通狀態以及阻斷狀態，具有方便使用效果。
