Abstract: The catalyst RhCl(PPh₃)₃ was prepared from soluble rhodium salt and triphenylphosphine ethanol solution and used in the hydrogenation of α-pinene. Taking the conversion rate of α-pinene and the enantioselectivity of cis-pinene as the evaluation indexes, the effect of catalyst preparation conditions on the catalytic performance was investigated. The optimal conditions of catalytic preparation, catalyst life and reaction mechanism were also studied. The results showed that the most suitable catalyst preparation conditions were the ratio of phosphine to rhodium 4:1, the heating temperature 75 ℃, and the reflux time 4 h. The RhCl(PPh₃)₃ prepared under these conditions was used in the hydrogenation reaction of α-pinene. Under the optimal hydrogenation reaction conditions, namely α-pinene 4 g, the ionic liquid BMIM PF₆ 4 mL as reaction medium, reaction temperature 120 ℃, reaction pressure 1 MPa, speed 800 r/min, catalyst RhCl(PPh₃)₃ 5%, and reaction time 3 h, the average conversion rate of α-pinene reached 99.49%, and the average enantioselectivity of cis-pinane was 96.73%. The ionic liquid catalyst system was easy to separate from the product, and could be reused. The conversion rate could reach 91.19% at the second use. The ionic liquid was the medium, and the catalytic reaction mechanism of RhCl(PPh₃)₃ was the interaction of "ionic medium-center metal-substrate". The interaction of the charged ionic liquid with the center metal Rh made the coordination ability other ligands such as Cl^- weak, which was beneficial to the coordination activation of olefins.