The interfacial stability between electrolyte components and electrode materials plays a crucial role in the formation of the solid electrolyte interphase (SEI) in sodium-ion batteries. In this work, density functional theory (DFT) calculations are used to investigate the interface behavior and electronic interactions of five common electrolyte anions (PF6−, BF4−, ClO4−, FSI− and TFSI−) on MoS2 surfaces. To capture the influence of electrochemical conditions, the surface is analyzed under three different Na concentrations corresponding to 0%, 50%, and 90% electrode degree of sodiation. Multiple interface orientations are considered for each molecule to evaluate interaction energies, charge redistribution, electron localization function, work function, and electronic structure modifications at the interface. The results reveal distinct interaction mechanisms depending on the anion and sodium content. BF4− exhibits strong interaction at low Na concentration, which weakens significantly upon sodiation. ClO4− shows a reduction in interaction strength despite relatively similar charge redistribution, accompanied by changes in electron localization associated with Na. In contrast, PF6− does not form a stable interface configuration and undergoes reorientation with increasing Na, favoring interactions with intercalated Na rather than the MoS2 surface. TFSI− exhibits a strong dependence on molecular orientation, with more stable configurations associated with oxygen coordination. These findings provide atomistic insight into the evolution of interfacial interactions in sodiated MoS2 and their possible implications for SEI formation in sodium-ion batteries.