On-site cardiopulmonary resuscitation: 1, chest compressions, so that both elbow joints straight, after overlapping hands with the root of the palm of one hand press the lower part of the patient’s sternum, vertical force downward, the depth of compressions is 5-6cm, the frequency of compressions is 100-120 times per minute. 2, artificial respiration: compressions after 30 times to give two artificial respiration. The airway must be opened before artificial respiration, and if there is a foreign body in the mouth or a denture, the foreign body must be removed before opening the airway and performing artificial respiration. 2 artificial respirations must be completed within 10 seconds, then turn back to chest compressions, and so on alternately. After 5 groups of operation, determine whether the patient’s breathing and heartbeat have recovered. If there is no recovery, continue the above operation. 3, electric defibrillation: If there is an AED automatic defibrillator or other resuscitation equipment at the scene, a defibrillator should be installed immediately while CPR is being given. If ventricular fibrillation or ventricular flutter is found, immediate electric defibrillation is given. 4, emergency drugs: open intravenous access as soon as possible, static push epinephrine and other resuscitation drugs rescue treatment.