The invention discloses a blood collection device used during invasive artery monitoring. The blood collection device comprises an arterial duct, a pressure connection tube, a pressure sensor, a continuous washing system and an electronic monitor, wherein the pressure connection tube is filled with liquid and provided with a switch. The blood collection device is characterized in that the pressure connection tube is provided with a blood collection plug, a three-way plug valve and an injection syringe, the blood collection plug is arranged on the part, on the root of a palm of a patient, of the pressure connection tube, the three-way plug valve is arranged between the blood collection plug and the injection syringe, and the injection syringe and the pressure connection tube are formed at a time. During blood collection, the injection syringe sucks the liquid in the pressure connection tube, blood is sucked to the position of the blood collection plug, a blood taking needle punctures the blood collection plug and the blood is collected; after blood collection is finished, the liquid sucked out by the injection syringe is injected into the pressure connection tube, waste of the blood of the human body of avoided, and pulsating pressure produced during injection of the injection syringe can reduce the blood vessel blocking probability; meanwhile, no bloodstain is formed on the blood collection position, and therefore the blood infection probability of the patient is reduced; in addition, blood collection steps are simplified and the quantity of consumables is reduced.