The latest CPR guideline suggests that for adults, children and infants, the frequency of single person CPR should be not less than 100 compressions per minute, and the ratio of compressions to ventilation should be 30:2. The steps of CPR mainly include chest compressions, opening the airway, and artificial respiration. First of all, chest compressions, chest compressions are usually performed by the operator with the palms of both hands overlapping alternately, the heel of the palm of the hand is placed on the lower part of the sternum, the elbow joint is straightened, and vertical downward pressure is applied, the depth of the general compression is 5-6cm, and the frequency of the compression is more than 100-120 times per minute. After 30 chest compressions, the airway must be opened, and before opening the airway, foreign objects in the mouth must be removed, if there is vomitus, it must be excluded, and if there are dentures, they must be removed.