Objective To develop a method for the separation and preparation panaxynol. Methods Panax Notoginseng was extracted by SEF-CO_2, and absorbed by silica gel to remove most of the polar impurities. Panaxynol was preparated with RP-HPLC. Result Panaxynol was identified by UV、IR、MS、NMR,and the purity of panaxynol reached 98%. Conclusion The developed method is simple, reproducible and easy to operate. The solvent is cheap,with low boiling point and easy to recovery property.