Frequent spitting while smoking is mainly due to a physiological reaction after the smoke stimulates the body; it may also be due to pharyngitis and other reasons; it is recommended to quit smoking in time. Tobacco combustion will stimulate the human body’s oral mucosa, pharyngeal mucosa, causing mucosal secretion of mucus increases, producing saliva, phlegm, etc., causing spitting, spitting and other actions, which is the human body to deal with external stimuli of a defensive reflex. In addition, because phlegm and saliva are discharged through the mouth, sometimes the spit out after smoking is not saliva, but phlegm produced by pharyngitis caused by smoking. Smoking is harmful to health, and long-term smoking may cause lung cancer, COPD and other diseases. Spitting, spitting and other defense reflexes, suggesting that the body is not adapted to the stimulation of tobacco, it is recommended to quit smoking in a timely manner.