Among the vinyl chloride production processes, ethane oxychlorination is the most economical and environment-friendly process but constrained by the lack of high performance catalysts for industrial applications. In this work, FeCl₃–KCl/Al₂O₃ catalysts with different molar ratios of K/Fe were prepared by a co-impregnation method and applied to ethane oxychlorination. The FeCl₃–KCl/Al₂O₃ catalyst with K/Fe = 2 exhibited enhanced catalytic performance with the highest conversion of C₂H₆ (99.1%) and the best selectivity to C₂H₃Cl (74%) under the optimal conditions of 400 °C, C₂H₆ : HCl : air = 1 : 3 : 5.5 (volume ratio) and GHSV = 4560 h⁻¹. It was found that the enhanced catalytic performance could be attributed to the formation of KFeCl₄ from KCl and FeCl₃ and the change of the reaction process. Besides, KCl is in favor of weakening the interaction between the active species and support. The reduction activation energy of Fe(III) → Fe(II) is efficiently reduced by KCl addition. The FeCl₃–KCl/Al₂O₃ catalyst may be a potential catalyst for industry due to its simple composition and convenient preparation.