Radioactive ray is a penetrating particle beam radiated from the nucleus when an unstable element decays, and is divided into A ray, B ray, and C ray, of which C ray has the strongest penetrating power. In addition, radiation has certain harm to the environment and human body. It is known that radiation and radioactive substances are harmful. What exactly are the hazards to human body? The human body is exposed to radiation, and as the dose of radiation action increases, it is possible that certain harmful effects may occur randomly. For example, it may induce leukemia, thyroid cancer, bone tumors and other malignant tumors; it may also cause genetic material in the human body to undergo genetic mutations and chromosomal aberrations, resulting in congenital malformations, miscarriages, stillbirths, infertility and other conditions. However, the chances of this happening are low. The degree of risk is generally not more than what is currently acceptable to people. In the case of an accident, if the human body is exposed to a certain dose of radiation, some definite expected harmful effects may occur. For example, the human eye crystal once by more than 2 Gorey X or γ-ray exposure, after 3 weeks may appear lens clouding, the formation of cataract; human skin by different doses of radiation, respectively, hair loss, erythema, blisters and ulcers necrosis and other damage; in addition, may also cause anemia, reduced immune function, shortened life expectancy, as well as endocrine and reproductive dysfunction. When the human body in a short period of time (a few seconds to a few days) by more than 1 Gorey dose of radiation exposure, it will produce acute radiation sickness, life-threatening; the body in a longer period of time by the role of ultra-dose limit of radiation may lead to chronic radiation sickness, resulting in hematopoietic tissue damage mainly chronic radiation damage to the whole body. This situation is mainly for the occupational personnel engaged in radiation work, rarely occurs in the public, and does not include local medical exposure. Of course, radiation can also be used for the benefit of humans. The use of radiation in hospitals is often used for the diagnosis and treatment of certain diseases in the human body and can have unique effects. At the same time, it is also widely used in agriculture and industry, scientific research and defense construction. The key for us is to use it scientifically and strictly strengthen the protection so that the human body is protected from its hazards.