Abstract: Geological cement was invoked as the basic material for solidification. The leaching rate (R_n), cumulative leaching fraction (P_t), phase, micro-structure and other parameters of Sr(Ⅱ), Cs(Ⅰ) and U(Ⅵ) in the geological cement solidified body during the leaching period of up to 2.5 years were investigated. Leaching rules and mechanisms of three simulated nuclides were studied, and the long-term leaching model was constructed. The experimental results show that the leaching experiment is always carried out in an alkaline environment during the whole leaching cycle, which is beneficial to the adsorption of nuclides by geological cement. The conductivity of leaching solution still changes slowly after the concentration of nuclides reaches equilibrium, which indicates that other ions in cement solidified body also participate in dissolution leaching, which is confirmed by XRD test result. The R_n and P_t values of Sr(Ⅱ), Cs(Ⅰ) and U(Ⅵ) at 42 d are all lower than the national standard, indicating that the cement has good-solidification ability for these three nuclides, but the retention ability for U(Ⅵ) and Sr(Ⅱ) is much higher than that for Cs(Ⅰ). The one-dimensional decay leaching model can predict the long-term leaching behavior of Sr(Ⅱ), Cs(Ⅰ) and U(Ⅵ) in the solidified geological cement over a period of up to 2.5 years.