The invention discloses a method for preparing a Pd / C catalyst for one-step-method synthesis of alkyl cyclohexyl anone liquid-crystal intermediates. The catalyst comprises Ti doped modified activatedcharcoal, an active ingredient Pd and auxiliaries, wherein the auxiliaries comprise Zn and Sn. The preparation method comprises the steps: 1. preparing the Ti doped modified activated charcoal; 2. preparing a Pd active ingredient precursor; 3. adding a stabilizer, a precipitant and a reducer into the Ti doped modified activated charcoal, carrying out pulping with pure water, then, carrying out uniform stirring, dripping the Pd active ingredient precursor, and carrying out uniform stirring, so as to obtain mixed pulp; 4. heating up the mixed pulp, then, carrying out heat-preserving reduction, carrying out cooling, then, adding a ZnCl2 solution and a SnCl2 solution, carrying out stirring, and then, carrying out filtering, thereby obtaining the Pd / C catalyst for one-step-method synthesis of the alkyl cyclohexyl anone liquid-crystal intermediates. The catalyst prepared by the method has good selectivity to alkyl cyclohexyl anone, a reaction system can achieve very good yield without addingNa2CO3 and the like, the operation is simplified, and the cost is reduced.