Precautions for the use of AED include: 1, AED mainly for loss of response, loss of breathing or only dying gasping patients, should not be used for other patients, including patients with chest tightness, chest pain, to avoid AED diagnostic errors or unnecessary treatment; 2, the use of the process needs to avoid patients with too much water in the chest, more chest hair patients need to remove chest hair; if there is a patient installed pacemaker and other special circumstances, electrode patches need to avoid the pacemaker; 3, can be used in the snow or wet ground, avoid patients in the water when the use.