A device for puncturing a heparin cap is disclosed, including: a connecting unit, adapted to be coupled to a medicinal fluid supply device in fluid communication； a guiding unit, adapted to accommodate at least one part of the heparin cap； and a puncturing unit for puncturing the heparin cap, configured to be in fluid communication with the connecting unit and at least partially located on a predetermined position in the guiding unit. The predetermined position is configured so that in the process of at least one part of the heparin cap entering into the guiding unit, the puncturing unit is inserted into a sealing rubber of the heparin cap at an appropriate location on the heparin cap and an appropriate angle relative to the heparin cap, and ultimately penetrate through the sealing rubber. With the device, the medical worker can complete the puncture of the heparin cap safely, easily and effectively. Meanwhile, the device can greatly reduce or eliminate the unnecessary waste of the medicinal liquid during the subsequent infusion, and facilitates the medical worker to completely wash the medicinal liquid remained within the heparin cap off.
