Abstract: Molten salt electrolytic refining is a critical step in the pyroprocessing of spent nuclear fuel. In order to clarify the electrochemical behavior and separation mechanisms of uranium and plutonium in liquid cadmium cathodes, and to reveal the competitive reaction patterns between actinide and lanthanide elements, the electroreduction and separation characteristics of U³⁺, Pu³⁺, and representative lanthanide ions in LiCl-KCl molten salt were systematically investigated in this paper. A series of electrochemical measurements and separation experiments were carried out under controlled conditions to evaluate the deposition behavior and separation efficiency. The experimental results indicate that under different Pu/U molar ratios, the residual rates of uranium and plutonium in the molten salt remain as low as 0.83% to 0.99%, while their recovery yields in the cathode product range from 92% to 94%. These values demonstrate the high efficiency of the liquid cadmium cathode for actinide recovery. With respect to the separation of actinides from lanthanides, which is one of the major challenges in partitioning and transmutation strategies, the results show that uranium and plutonium exhibit residual rates of 0.99% and 0.94%, respectively. The corresponding product recovery yields fall within the range of 90.6% to 93.4%, indicating that both elements are effectively collected at the cathode while most lanthanides remain in the salt phase. The separation performance between uranium and lanthanide elements was further evaluated by calculating separation coefficients, which are found to range from 32 to 50. These values reflect a favorable selectivity for uranium over lanthanides under the given experimental conditions. In summary, the findings of this study provide quantitative insights into the electrochemical behavior and separation performance of key actinides in molten salt media. The results contribute to a better understanding of the underlying separation mechanisms and support the development of more efficient pyrochemical processes for spent fuel treatment.