<p>Understanding the structural intricacies of LiF-PrF₃-Pr₆O₁₁ molten salts is of paramount importance for advancing praseodymium electrolysis technology. In this study, the ion structure of the LiF-PrF₃-Pr₆O₁₁ molten salt system was analyzed by combining <i>in situ</i> high temperature Raman spectroscopy and density functional theory (DFT) within the temperature range of 1203~1323K. Additionally, the ions present in the melt were quantitatively analyzed using Raman scattering cross section (RSCS). The results indicate the presence of PrF₆^3- (<i>O</i>_<i>h</i>), Pr₂F₈^2- (<i>C</i>_<i>1</i>), Pr₂F₉^3- (<i>S</i>_<i>4</i>), and Pr₂F₁₀^4- (<i>D</i>_<i>2h</i>) praseodymium fluoride anions in the LiF (15 wt pct)-PrF₃ (85 wt pct) melt. The predominant ions in the melt transform from Pr₂F₈²⁻ and Pr₂F₁₀^4- to PrF₆^3- and Pr₂F₉³⁻ with increasing temperature. The PrOF₃²⁻ (<i>C</i>_<i>1</i>), PrOF₅^4- (<i>C</i>_<i>4v</i>), Pr₂OF₆^2- (<i>C</i>_<i>2v</i>), and Pr₂OF₈⁴⁻ (<i>C</i>_<i>2</i>) praseodymium oxyfluoride anions were formed after 2wt pct Pr₆O₁₁ was added to the LiF-PrF₃ molten salt. The stability of praseodymium fluoride ions decreases as the temperature rises, resulting in the conversion of these ions in the molten state into Pr₂OF₆^2- and Pr₂OF₈^4- anions.</p>