Bone age film done twice in three days is OK, usually does not have too much effect on the patient. The so-called bone age film, in fact, is the most common clinical X-ray, through the X-ray fluoroscopy principle to shoot the epiphysis of the wrist, knee joints and other parts of the bone, reflecting the development of the child’s bones. The impact of X-rays mainly comes from ionizing radiation, generally limbs X-ray once the dose is about 0.01mSv, two times is 0.02mSv, normal human body can generally withstand about 7Sv, 1Sv=1000mSv. Therefore, two times the X-ray dose, far lower than the dangerous dose, is safe. Many parents worry that continuous X-ray examination will induce leukemia, thyroid disease, affect the normal physical development and other conditions, in fact, completely unnecessary, our normal life will also have radiation, such as sunlight, cell phones, computers and so on. Therefore, it is routinely recommended that children who have had X-ray examinations eat more fresh vegetables and fruits and participate in more physical exercise to increase the body’s metabolism, which helps the organism repair itself.