When performing CPR, the patient should be placed flat on a hard floor and 30 external cardiac compressions should be performed first. When performing external cardiac compressions, interlock the fingers of both hands, overlap the roots of the palms, place the roots of the palms at the midpoint of the nipple line, straighten the elbows, and press vertically and evenly downward. The frequency of compression is 100-120 times/minute, the depth is 5-6 cm. when the compression should let the thorax completely rebound, the compression is too fast, too slow or the compression force is not enough, the compression force is too large may lead to poor compression effect, and even possible complications. After compressions, the mouth should be cleaned of foreign bodies, the airway should be opened, and then two artificial respirations should be performed. Artificial respiration can be performed mouth-to-mouth or with a simple respirator, and the patient’s chest should be observed to rise and fall when blowing. The time between blowing and inhaling is 1 second, and the air delivery should not be too fast or too excessive. The resuscitation process is repeated in the ratio of 30 compressions followed by 2 artificial respirations, and the 5 cycles are evaluated after about 2 minutes. During resuscitation, if an AED, or automated external defibrillator, is available, use the AED for first aid as soon as possible.