Chest X-ray is an X-ray that passes through human tissues to form an image on a fluorescent screen or film.X-ray is electromagnetic radiation, and when the human body is irradiated with a dose that exceeds a certain limit, it will block the normal division and proliferation of human cells and lead to abnormal proliferation, which affects the human body and may cause cancer, and may cause malformation to the fetus. However, the radiation of chest radiography is relatively low, after the necessary protection during the examination, the radiation of chest radiography is not enough to affect the health of human body. x-ray chest radiography is quick and easy, the image is clear, the contrast and clarity is better, and it can be retained as an objective record for the convenience of reviewing and comparing, therefore, at present, there are still more cases of chest radiography in the clinic. For infants and young children, preparation for pregnancy and pregnant women and other special groups should be careful to choose X-ray examination.