Abstract: Based on multi-physics coupling software COMSOL, a three-dimensional numerical model of uranium chloride electrodeposition behavior, in which the electrolytic cell serves as anode and the double graphite rod serve as cathode, was established in LiCl-KCl molten salt system. With the research in the movement of uranium ions and the real-time calculation of the cathode geometry, the change of the thickness of uranium electrodeposition with time is worked out. The relationship between the uranium deposition behavior and the position of the cathode surface, molten uranium ion concentration, reaction temperature, average current density is obtained. In this research, the simulation results are compared with the experimental data of uranium chloride electrolysis. The calculations are well fitted to the experimental results, and the reliability of the uranium electrodeposition behavior simulation is proved. The simulation results can provide a design reference for the extraction of the uranium from the spent fuel by dry reprocessing.