1. Select a suitable pen type two-way blood sampling needle, hold the needle sleeve at both ends of the pen type needle with both hands and unscrew it in the opposite direction to remove the white needle sleeve at one end (the end with rubber sleeve);
2. Screw the needle end of the head cover into the sleeve in a clockwise direction;
3. Remove the color end needle sleeve, select the thick and straight main vein for venipuncture;
4. After the successful venipuncture, the vacuum blood collection vessel was put into the sleeve, the flange of the sleeve needle holder was stuck by the index finger and the middle finger, the pressure was exerted on the bottom of the tube in the opposite direction of the thumb, and the tube plug puncture was carried out;
5. After blood collection, the blood collection vessels containing additives were gently reversed and mixed for 5-6 times;
6. After blood collection, the last collected tube shall be removed from the needle holder, and then the venipuncture needle shall be pulled out and placed in the recovery box.