Abstract: In recent years, the incidence of skin cancer, especially squamous cell carcinoma, has increased significantly. About 90% of skin cancers are associated with ultraviolet radiation damage. Upon exposure of the skin to ultraviolet rays, especially UVB (290–320 nm) and UVA (320–400 nm), epidermal melanocytes migrate to adjacent keratinocytes by synthesizing melanin, thus providing light protection for the skin. A series of damage reactions, including tanning and inflammation, cell DNA damage, and photocarcinogenesis, occurred after the skin was stimulated by excessive ultraviolet radiation. Recent studies have found that visible light (400–700 nm) and ozone can also cause skin damage. The skin damage caused by environmental exposure is mainly attributed to the production of reactive oxygen species, which cause oxidative damage to protein, lipid, and nucleic acid, followed by a series of complex reactions within the skin. Damaged skin cells cause inflammatory reactions, resulting in ultimate damage to the skin. Therefore, understanding the mechanism of photoinduced skin damage and developing correct radiation protection measures are important for the treatment and prevention of related diseases. This review summarizes the effects of sunlight, including ultraviolet, visible, and ozone on skin damage, as well as the research on gene loci of suntan caused by sunlight, to explore new ways to prevent and treat skin damage caused by solar radiation.