Abstract: Due to the strong radioactivity, high toxicity and complex composition of high level liquid waste (HLLW), it is a worldwide problem to separate cesium from HLLW. For many years, scientists all over the world have been exploring methods to separate cesium from HLLW, in an effort to find a suitable separation technology of cesium for industrial applications, to solve the problem of cesium separation from HLLW. On the one hand, China’s existing defense HLLW with high concentration, high salt content and strong radioactivity needs to be properly treated and disposed to avoid the long-term storage risk. On the other hand, with the rapid development of nuclear power and the industrialization of commercial spent fuel reprocessing in China, the treatment and disposal of HLLW has become increasingly prominent. To meet these requirements, Chinese scientists finished a lot of research work on the separation of cesium from HLLW and obtained a series of achievements. In recent decades, ion-exchange, extraction chromatography and solvent extraction were mainly applied to separate cesium from HLLW in China. Ion-exchange technology based potassium titanium hexacyanoferrate and solvent extraction method based calixcrown were developed successively and tested in hot test and pilot facility. The technology of calixcrown extraction cesium（CCEC） from HLLW not only meets the requirement of industrial application, but also is in the forefront of the world.