Yawning is a physiological phenomenon that occurs when the human body is fatigued, and it can temporarily increase oxygen uptake, promote carbon dioxide discharge, relax the muscles, and relieve one’s fatigue. When a person is overworked and mentally tired, it will stimulate the physiological response of yawning. Yawning when the big mouth breathing air, inhale more oxygen, discharge more carbon dioxide, can increase the brain’s blood oxygen content, so that the spirit of people better. At the same time, the muscles of the whole body are also in a state of relaxation, get a rest. When yawning, people do not talk, the brain is also in a relaxed state, so that people briefly from a variety of busy or annoying things out. It can relax the body and mind for better work and study. Yawning is also a kind of self-protection, reminding a person to rest and relax early, so as not to overwork and lead to various diseases.