If an adult is in respiratory and cardiac arrest, the ratio of chest compressions to artificial respiratory ventilation is 30:2 when resuscitated by two people, i.e. one of the rescuers performs 30 regular chest compressions, the depth of compressions is 5-6 cm, the frequency of compressions is 100-120 times/min, it takes about 15-18 seconds to perform 30 compressions, and stop compressions after 30 compressions. Another rescuer immediately mouth-to-mouth artificial respiration twice, each blowing for more than a second, and then stop blowing to the patient, and then continue to rescue in accordance with the ratio of compressions and ventilation 30:2, rescue 5 rounds, that is, compressions 150 times, ventilation 10 times, about two minutes, check the patient’s breathing and heartbeat to see if there is recovery, no recovery, continue to rescue according to this ratio.