The effect of TiO₂ on viscosity of low-fluoride CaF₂-CaO-Al₂O₃-MgO-Li₂O slag for electroslag remelting was investigated under the continuous cooling conditions and the FTIR and the Raman spectroscopy were employed to analyze the correction between the quenched slags and the corresponding structure in the study. It can be found that the slag viscosity lowers as gradually increasing TiO₂ content, and when TiO₂ content up to 13.1%, the corresponding viscosity values slowly decrease from 0.067 Pa?s, 0.059 Pa?s, 0.056 Pa?s to 0.054 Pa?s with the temperature increases from 1743 K, 1793 K, 1843 K to 1893 K and at higher temperature of 1843 K and above, TiO₂ addition has only a relatively small effect on lowering the slag viscosity. The calculated activation energy of viscous flow decreases from 58.0 kJ/mol, 47.7 kJ/mol, 42.8 kJ/mol to 38.6 kJ/mol as increasing TiO₂ content from 0, 4.3%, 8.7% to 13.1%. Additionally, the FTIR results reveal that with the addition of TiO₂, [AlO_nF_4-n]-tetrahedral complexes and [AlO₄]-tetrahedra network structures depolymerized, but [AlO₆]-octahedra is not found in the slag. Simultaneously, it can be seen by Raman analysis that with the addition of TiO₂, leading to the depolymerization of the Al-O-Al linkage in the [AlO₄]-tetrahedra network structures, the transformation of part Q^₄ units to Q^₂ units, and the forms of O-Ti-O and Ti-O-Ti chains. These results suggest that polymerization degree of these slags decreases as increasing TiO₂ content, which is beneficial to simplify slag structure. Finally, the changed slag structure is in good agreement with the slag corresponding to the varying viscosity.