L-menthol was synthesized by using d-citronellal as raw material.The optimal reaction conditions were selected by investigating the reaction temperature, reaction time, catalyst dosage and catalyst steric hindrance. The results showed that the optimal reaction conditions were that toluene as solvent, d-citronellal as starting material, aluminum atom as the center, triphenylphenol as ligand, the amount of catalyst was 1% (mole fraction), reaction temperature was 0 ℃，the reaction time was 3 h, and an intermediate product was obtained by distillation under reduced pressure, followed by hydrogenation reduction to obtain 1-menthol, the total yield was 76%, and the GC purity was above 99%.