Automatic External Defibrillator (AED) use method includes four steps: “open, stick, plug, electricity”. 1. Turn on: Place the device on the left side of the patient’s body, turn on the power switch or lift the monitor cover, and then you should operate according to the voice of the device. 2. Paste: take out the electrode sheet and paste it on the chest wall of the patient, the position of one is on the outer side of the left nipple, the upper edge of which is about 7cm away from the armpit; the other one is on the right upper chest wall (below the clavicle). If the patient sweats a lot, the skin should be dried with a towel; if the patient has too much chest hair, try to stick the electrodes firmly; if it is not effective, the chest hair should be removed and then pasted. 3. Insertion: It takes 5-15 seconds to analyze the heart rhythm after inserting the plug of the electrodes into the jack of the defibrillator. At this time, emergency personnel and bystanders should not contact the patient to prevent interference with the analysis. 4. Electricity: Analyzing the results suggests that when defibrillation is performed, the electrode button is pressed without anyone touching the patient. Immediately after defibrillation is completed, continue cardiopulmonary resuscitation (manual chest compressions and artificial respiration), and repeat until emergency personnel arrive. If defibrillation is not necessary after rhythm analysis, continue CPR. The use of AED should grasp the principle of “listen to what it says, follow what it does”, which simply means to follow the voice prompts and screen display of the AED. Strictly follow the prompts when using the AED, to avoid blind operation, resulting in adverse consequences.