The steps of primary 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 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, and if there is vomitus, it must be excluded, and if there are dentures, they must be removed. After removing the foreign body from the mouth, the airway should be opened, and then two artificial respirations should be performed, and the chest must be seen to rise and fall when artificial respiration is considered to be effective. After two artificial respiration, then switch back to 30 chest compressions, the ratio of chest compressions to artificial respiration for single person CPR is 30:2, after five sets of chest compressions and artificial respiration, you can pause for a while to observe whether the patient’s breathing and heartbeat have recovered, and if they have not recovered, continue the above operation.