Abstract: In order to explore the extraction and separation performance of actinide nuclide by microorganism, the enrichment and reduction effect of model microorganism Saccharomyces cerevisiae on ²³⁹Pu of actinide nuclide in medium-high discharge waste liquor was preliminarily studied by chemical pretreatment and wet digestion method. The results showed that more than 99% of ²³⁹Pu removal could be achieved at pH 5 by living and dead S. cerevisiae with a microbial volume reduction of 97% after the ashing treatment. The adsorption ability was reduced significantly the ²³⁹Pu biosorption capacity of S. cerevisiae with deproteinization and deacetylation treatment. The wet digestion results showed that about 75.64% of ²³⁹Pu was complexed on the cell surface, while the remaining 24.36% was stabilized either inside or outside the cell after 96 h. The radioactivity of ²³⁹Pu(Ⅲ) was reduced from 7.35×10⁶ Bq/L to 2.30×10³ Bq/L after six rounds of batch adsorption of of S. cerevisiae biosorption. The total alpha radioactivity of the real medium radioactive liquid waste could be reduced by 2 orders of magnitude with more than 98% removal of the actinide nuclide content after two rounds of S. cerevisiae biosorption. However, total beta and gamma radioactivity was only be reduced by less than 10%. The presented results indicate that bio-adsorbents such as S. cerevisiae can potentially be used to extract and separate actinides from the real radioactive wastewater.