The biological effects of UV include sterilization, treatment of skin diseases, melanogenic effects, health effects, promotion of vitamin D production, pathogenicity and other effects. Germicidal effect of ultraviolet light: high-frequency short-wave ultraviolet light is extremely destructive to microorganisms and can kill bacteria. The black spot effect of UV: UV with a wavelength of 280-320nm can darken the skin, which is the black spot effect of UV. This band of ultraviolet light can make the skin metabolism speed up, skin growth and thickening of the skin. This band of ultraviolet light can treat skin diseases like psoriasis and vitiligo. UV health effects on the human body: UV wavelengths in the UV wavelengths of 280-320nm irradiation of the human body, so that the skin produces many active substances, thus playing a role in health care. Promote the production of vitamin D: ultraviolet rays from the sun can promote the production of vitamin D and can promote calcium absorption. Pathogenicity of ultraviolet rays: ultraviolet light acts strongly on the skin, light dermatitis can occur, and serious skin cancer can also be caused. Ultraviolet light acts on the central nervous system, can appear headache, dizziness, elevated body temperature and so on. Acting on the eyes, can cause conjunctivitis, keratitis, known as photophthalmitis, may also induce cataracts. Long-term ultraviolet radiation is most likely to cause the skin to produce a variety of color spots. Therefore, even in the cold winter, it is recommended to apply barrier cream or sunscreen for outdoor activities.