A drug injection device comprises a main body case, a drug syringe mounting component, a piston, a drive mechanism, a controller, and means for locking the lid during operation of the drug injection device. The main body case has a lid and a base and an injection needle let-in/let-out opening. The drug syringe mounting component is provided inside the main body case, and allows a (filled) drug syringe to be mounted therein. The piston is movable with respect to the drug syringe mounting component. The drive mechanism drives the drug syringe mounting component and the piston. The controller is electrically connected to the drive mechanism. The means for locking the lid during operation of the drug injection device is activated and deactivated by movement of the drug syringe mounting component when the lid is closed.本發明係關於藥物注射裝置，其包括一主體外殼、一藥物注射器安裝組件、一活塞、一驅動機構、一控制器以及一在藥物注射裝置的操作期間用於鎖定蓋體的構件。該主體外殼具有一蓋體、一基座、一使注射針頭進或出的開口。藥物注射安裝組件係配置於該主體外殼的內側，並允許一(已填滿)藥物的注射器安裝其內。該活塞可相關於該藥物注射器安裝組件移動。該驅動機構驅動該藥物注射器安裝組件以及該活塞。該控制器係電力連接至該驅動機構。該在藥物注射裝置的操作期間用於鎖定蓋體的構件係在蓋體關閉時，被藥物注射器安裝組件的運動所啟動以及停止。
