CAB cardiopulmonary resuscitation (CPR) is a kind of emergency medical rescue method for patients who have no respiratory response. the three letters of CAB stand for the three steps of chest compression, opening the airway and artificial respiration respectively. Cardiopulmonary resuscitation order is also in accordance with the order of CAB, in cardiopulmonary resuscitation, the main operating steps can refer to the following: First, chest compression, the operator needs to press the patient on both sides of the nipple connected to the midpoint of the position of the left palm close to the midpoint, the right hand overlap the left hand after crossing the arm, the arm is straightened, with the upper body of the strength of the pressure, the frequency is best to control the 100 times per minute, the time interval between compressions should not be more than 5 seconds. The interval between compressions should not exceed 5 seconds. Second, open the patient’s airway after compression, use the method of tilting the head and lifting the jaw, remove the secretions or dentures in the patient’s mouth. Third, artificial respiration, the operator needs to use mouth-to-mouth way to deliver oxygen to the patient, the frequency of this operation is generally 30 times after the pressure of artificial respiration twice. Repeat this operation until the patient’s vital features are restored, it should be noted that before this operation, but also to call the 120 telephone waiting for first aid.