The distribution and competitive behaviors of phosphotungstic acid and ferric chloride in the TBP–HCl–H₂O system were investigated by controlling the extractant concentration and the solution environment. The results revealed that phosphotungstic acid exhibited a strong affinity for TBP with decreasing TBP concentration. Higher acidity significantly improved the W extraction efficiency with TBP, and the lower Cl^- concentration reduced the extraction efficiency of Fe. As the organic phase approached saturation point, phosphotungstic acid competitively displaced Fe to combine with TBP. The hydrogen bond structure (P=O·HO—P—W—O) between phosphotungstic acid and TBP was characterized by FT-IR, and the salting-out effect induced by FeCl₃ was elucidated. In summary, high acidity is beneficial for exhaustive extraction of W, and an effective W/Fe separation can be achieved by reducing the concentrations of TBP and Cl^-.