In this paper, a solvent extraction system is applied to separate the mixture of mandelonitrile (MN) and mandelonitrile acetates (MA) for the first time. The basic consistence of the system is water and n-hexane with the phase ratio of 1.0. Operation parameters such as temperature, the pH value in the aqueous phase, and the concentration of the mixture and benzaldehyde were investigated to find the optimal conditions. When the temperature was 30 degrees C and the pH value in the aqueous phase was 2.0, a three-stage extraction was performed. The purity of MA in the organic phase was more than 99% (wt) with the yield of 87.7%. And the purity of MN in the aqueous phase was 98.8 % (wt) with the yield of 92.6%. This extraction system can separate the mixture of MN and MA efficiently.