1.Patients should relax their mind, expose their arms, and the local skin should be kept dry; 2.The medical staff will tie a tourniquet 5-8cm above the puncture site, and patients should keep their fists clenched; 3.Patients should actively cooperate and not dodge and move when the medical staff puncture the needle into the blood vessel; 4.After the blood collection is completed, patients need to press the puncture site with a cotton swab for 3-5min.