Smoking may have some impact on male fertility, especially men who are in the period of preparation for pregnancy should avoid smoking. Tobacco contains nicotine, tar and a lot of other harmful substances, which will damage the function of the interstitial cells of the male testes and affect hormone secretion, thus affecting the quality of semen. Moreover, harmful substances such as nicotine may also harm sperm, affect sperm vitality, and even lead to sperm deformities. During the preparation period, men must avoid smoking as well as avoid being in a second-hand smoke environment. All of these conditions may have an impact on sperm quality. In addition to this, smoking may also affect cardiopulmonary function and cause other systemic diseases, which should also be taken seriously. If a man’s fertility is abnormal, it may be related to other factors, and it is recommended that he seek medical attention to identify the cause of the problem and treat it accordingly.