Industrial Pr-Nd oxide product has different physical properties, and shows different behaviors in the process of producing Pr-Nd metal by molten salt electrolytic. To meet the specific requirements of molten salt electrolysis for the physical properties of Pr-Nd oxide, different physical properties of raw materials such as particle size, specific surface area, morphology, bulk density and mobility were compared by chemical analogy experiment and actual production, the influence of physical properties of Pr-Nd oxide on its electrolysis process were studied, and the physical properties of the suitable electrolytic Pr-Nd oxide are quantified. The results show that particle size and morphology are the most important physical properties of Pr-Nd oxide in the electrolysis process. Pr-Nd oxide with good physical property requires the particle size is uniform and not too big or small. Additionally, the microstructure should not be over dispersed, but with agglomerate status, besides the micro surface should have porous structure to avoid melting phenomenon. The physical properties of raw materials produced by the method of oxalic acid precipitation are more stable than that by the ammonium bicarbonate precipitation method, and the good and stable physical properties are more suitable for molten salt electrolysis. So the oxalic acid precipitation method can be used as reference of the ammonium bicarbonate precipitation method.