Pt/γ-Al2O3 catalysts promoted by K2SO4 were prepared by the impregnation method.Pt-K/γ-Al2O3 catalysts with different Pt distributions could be prepared by adding different HCl contents to the impregnation solution and were used for preparing o-phenylphenol(OPP)from o-cyclohexenylcyclohexanone(Dimer)dehydrogenation.These catalysts were characterized by XRD，H2-TPR，BET and EPMA.The results showed that the interaction of Pt species with support，the structure of the catalyst and Pt distribution were modified by adding different HCl contents to the impregnation solution.The catalyst with 0.50％HCl concentration of the impregnation solution had the largest BET surface areas optimum Pt depth and weaker interaction between Pt and support.The residence time of intermediate products and OPP on the catalyst surface were adjusted，then the formation of byproducts was prohibited and the selectivity of OPP was obviously improved.The conversion of o-cyclohexenylcyclohexanone reached 100% and selectivity of o-phenylphenol were more than 90% at 0.12 g·g-1·h-1 of LHSV and 33 ml·g-1·h-1 H2 space velocity，and 380℃.