Lithium hydroxide is an important nuclear energy material, which plays an important role in regulating the chemical properties of water in pressure vessels during the operation of nuclear power plants. It is mainly used to regulate the pH value of the primary cooling water of pressurized water reactors. Because anion ions such as fluorine and chlorine have a strong corrosion effect on stainless steel vessels, which seriously affects the life of the reactor and is not conducive to the life extension of the reactor. Therefore, there are strict limits on the content of fluorine, chlorine and other impurity ions in the process of use. In order to determine the content of anionic impurities in lithium hydroxide, it is necessary to use effective analytical methods for determination. At present, ion chromatography has become the preferred method for the analysis and determination of trace anions in solution due to its simple operation, high sensitivity and outstanding advantages of anion analysis.