Abstract: Mixer-settler is widely used for solvent extraction in the nuclear Purex process and petrochemical industry because of its simple structure, strong process adaptability, and high stage efficiency. However, existing studies on mixer-settler extraction simulation rarely address the development of dynamic models. To fill this gap, this study developed a dynamic extraction model by coupling droplet mass transfer kinetics, extraction equilibrium relationships, and hydraulic parameters. The mixing chamber and the settling chamber were modeled independently. The differential equations of the mixing chamber were solved by the fourth-order Runge-Kutta method, and the differential equations of the settling chamber were solved by the finite difference method. The model also incorporated the influence of impeller speed on mass transfer efficiency and introduced a volume expansion-contraction correction term to account for solution volume changes. Therefore, the model can accurately simulate the transient concentration variations of uranium and nitric acid in both phases during extraction. In this study, the organic phase was adopted as the initial filling phase, regarded as the continuous phase, while the aqueous phase served as the dispersed phase. In addition, to verify the accuracy and robustness of the simulation model, a single-stage mixer-settler experimental platform was established, and the single-stage extraction experiments under different impeller speeds were carried out. The experimental data were then compared with the simulation results. Besides, literature data were also obtained to compare with the simulation results of multi-stage dynamic extraction model. The results show that the modeling results reach steady-state under all stirring speeds, with the maximum relative deviations of about 5.37% and 5.65% between the calculated and experimental uranium concentrations in the aqueous and organic phases, respectively. Regarding the multi-stage extraction results, the relative error between the simulated and experimental values of steady-state uranium outlet concentration in the organic phase is 4.7%. The maximum relative errors between the simulated and experimental values of steady-state nitric acid concentrations in the organic and aqueous phases are approximately 3.06% and 2.99%, respectively. The dynamic result analysis indicates that, due to the volume expansion effect and counter current characteristic, the concentration changes of nitric acid in both aqueous and organic phases in the mixer exhibit a trend of first decreasing and then increasing. In contrast, the uranium concentration in the organic phase shows a consistent upward trend. Additionally, the uranium concentration in the organic phase of the eighth stage first achieves 44.05 g/L within the single-stage residence time, followed by stabilization at 47.63 g/L. The developed dynamic model can also accurately predict the equilibrium time for extraction of the 8-stage mixer-settler, which is about 8 000 seconds, providing reliable predictive data for the equipment design and extraction process optimization of mixer-settlers.