As an unhealthy habit, smoking can not only induce lung cancer and cardiovascular disease, but also cause a decrease in human fertility. Cigarettes contain nicotine, carbon monoxide, cadmium and other harmful substances, which not only affect male testicular germ cells, inhibit the secretion of sex hormones and kill sperm, but also contain a variety of toxic chemicals, which can easily interfere with the normal spermatogenesis process of the testes, leading to a decrease in semen quality, which in turn causes a decrease in sperm fertility. For sperm, the integrity of DNA not only ensures the integrity of genetic information, but also has an important impact on the structure and morphology of sperm cells. Studies have shown that tobacco concentrates and their metabolites are rich in mutagenic and carcinogenic substances, which on the one hand cause sperm DNA synthesis to be blocked or mutated, and on the other hand can trigger DNA double-strand breaks and damage to sperm cell DNA through mechanisms such as re-repair damage. Numerous studies have confirmed that smoking can cause a decrease in the quality of male semen, and the decrease in semen quality is more pronounced as the duration of smoking increases and the amount of daily smoking increases. Therefore, we advise all men who smoke to throw away their cigarettes for the sake of your health and the health of your family, and for the sake of your own pregnancy.