The traditional angle of needle entry for venipuncture is 15° to 30°. After clinical practice, it is found that increasing the angle of needle entry between the needle and the skin is easier to puncture, and due to the large angle, the time to pass through the dermis is reduced, which can reduce the pain caused by needle entry or achieve painlessness. When infusing intravenous fluids, it is important to pay attention to the fact that the air inside the infusion dermatome must be evacuated before the infusion to prevent a large amount of gas from entering the blood vessels and causing air embolism, which can be life-threatening. The speed of infusion during the infusion is not recommended to be too fast, especially for people with heart disease, if the infusion is too fast, it may easily cause heart failure and other possibilities.