The best drug to perform CPR after cardiac arrest is epinephrine. For cardiac arrest patients who need to be resuscitated is cardiopulmonary resuscitation, the patient should be given first to determine the vital signs, view the patient if there is no consciousness, breathing, heartbeat, carotid pulsation, then cardiopulmonary resuscitation should be performed quickly, if there are rescue drugs should be given epinephrine injection. In addition, the principles of CPR must follow the order of C, A, B, that is, first should be performed chest compressions, then open the airway, and finally give artificial respiration, the ratio of compressions and ventilation should be 30:2. repeatedly five rounds of effective compressions and artificial ventilation after re-evaluation of the patient, if the patient is still not successful in CPR, epinephrine can be given again.