A drug dilution device suitable for a needle. The drug dilution device includes a casing, a liquid injection module, a control module and a connector. The casing includes a discharge port. The liquid injection module is set in the casing, and includes a liquid supply tank for diluting liquid, an infusion tube communicating with the liquid supply tank, and an infusion controller. The end of the infusion tube is set at the discharge. Port, the infusion controller allows a certain amount of diluent to be delivered via the infusion tube. The control module is arranged in the casing and is electrically connected with the liquid injection module, and is used to set the output volume of the dilution liquid output by the liquid injection module. The joint is used to connect the medicine bottle, cover the mouth of the bottle, and be detachably fixed to the discharge port. The joint has a mounting hole to hold the needle and connect the needle to the infusion tube.一種藥物稀釋裝置，適用於一針頭。該藥物稀釋裝置包含一機殼、一注液模組、一控制模組及一接頭。該機殼包括一出料口。該注液模組設於該機殼內，且包括容置稀釋液的一供液槽、連通該供液槽的一輸液管，及一輸液控制器，該輸液管的末端設於該出料口，該輸液控制器使一定量的稀釋液經由該輸液管輸送。該控制模組設於該機殼並與該注液模組電連接，用以設定該注液模組輸出稀釋液之輸出量。該接頭用以連接該藥瓶並遮蓋該瓶口且可拆卸地固定於該出料口，該接頭具有一安裝孔以固持該針頭，並使該針頭連接該輸液管。
