目的计算和测量医用诊断X射线与物质相互作用的能量及强度变化规律,研究其防护措施。方法根据X射线变化规律,计算直射线、散射线与透射线的能谱分布,分析并实验测量不同物质对X射线的屏蔽效果。结果 X射线经物质衰减后,强度变低,平均能量提高,能谱变窄;散射线能量和强度都小于直射线。不同物质对X射线屏蔽效果不同。结论铅是防护医用诊断X射线的理想材料。 Objective To calculate and measure the energy and intensity of the interaction between medical diagnostic X-ray and matter and to study the protective measures. Methods The spectrum distribution of direct rays, scattered rays and transmission lines was calculated according to the variation rule of X-ray. The shielding effect of different substances on X-rays was analyzed and experimentally measured. Results After X-ray attenuation, the intensity decreased, the average energy increased, and the energy spectrum became narrower. The energy and intensity of the scattered ray were less than that of the direct ray. Different materials have different X-ray shielding effects. Conclusion Lead is the ideal material for protection of medical diagnostic X-rays.