Abstract: National occupational health standard—Method of Dose Estimation Using Chromosome Translocation with Fluorescence in Situ Hybridization has been developed, which based on comprehensive collection, reading and analysis of relevant literature both abroad and domestic and the existing diagnostic criteria for radiation diseases of the China, and the repeated experimental verification. This standard is mainly applied for dose estimation for individuals who previously exposed to irradiation by accident, and provide the scientific diagnosis of radiation sickness. To better understand and implement it, the contents of this standard were interpreted in this article.