The detection of sperm DNA damage, as an important supplement to semen routine examination strategies, has been applied in some clinical andrology laboratories. What factors may lead to sperm DNA damage remains one of the concerns among many andrologists. Present studies show a variety of factors of sperm DNA damage, including age, environmental pollutants such as organophosphorus and organochloride pesticides, plasticizer, heavy metals such as lead, carcinogens such as polycyclic aromatic hydrocarbons (c-PAHs) and zearalenone (ZEA), male reproductive system diseases or systemic diseases such as varicocele, infection, tumor, spermatogenesis and maturation dysfunction, spinal cord injury and endocrine disorders, seasons and temperature, lifestyle, abstinence time, semen refrigeration, semen handling in vitro, and certain medications. Among them, spermatogenesis and sperm maturation dysfunction may be the most secretive factors, which are involved in the molecular mechanisms of sperm chromatin packaging and restructuring, such as the transformation of histone to protamine, single nucleotide polymorphism of genes, and the role of telomere, which may be one of the hotspots in the future studies of sperm DNA damage. Relevant researches in the future are expected to focus on the prevention of sperm DNA damage and clarification of its specific pathogenic mechanisms so as to provide some evidence for its treatment.