The ISO 13166 standard provides a test method for the determination of uranium isotopes in water quality using the α Light spectrum method. This method is suitable for the detection of uranium isotopes in water bodies (such as uranium-238 and uranium-235). The concentration value of uranium isotopes can be obtained through precise sample collection and processing procedures, combined with the analysis of α Light spectrum meters. This standard aims to provide a technical basis for environmental monitoring, nuclear energy-related research and water quality safety testing. Through this method, it can help to effectively assess the situation of uranium contamination in water bodies and provide support for research and management in related fields.