Chemical immobilization experiment of nuclide uranium in uranium tailings pond with nano-zeolite, potassium dihydrogen phosphate and modified biochar combined, the leaching features and morphological changes of uranium before and after immobilization was determined by toxicity characteristic leaching procedure (TCLP) and stepwise chemical extraction.TCLP results showed that after 30 days of immobilization with different stabilizers, the amount of uranium leaching from soil decreased by 42.13%~71.54% compared with the control group.Moreover,there was a significant negative correlation between soil pH and TCLP-extracted uranium content.Tessier results showed that the mass fraction of exchangeable and carbonate-bound uranium in soil decreased by 7.38%~26.06%, 1.43%~6.99% with different fixatives, while the organic-bound, Fe-Mn oxide-bound and residual uranium increased by 2.56%~3.64%,2.71%~17.47%, 4.07%~11.12% respectively. In the single fixed material experiment, the application of nano-zeolite with 6% soil mass fraction has the best stability effect,the proportion of exchangeable uranium in soil decreased by 15.68%.In the compound materials experiment, the best repair effect was obtained by adding three fixatives with a mass ratio of 1:1:1 and a total dosage of 6%,the proportion of exchangeable uranium in soil decreased by 26.06%.Therefore,the application of three fixatives combined can effectively reduce the activity of uranium in soil,to provide theoretical reference for the remediation of other radioactive contaminated soils.