数7级。To lower the solvent ratio and the energy consumption during the solvent recovery process, the methods of solvent recycling and parameter determination for the best extraction stage number, extraction temperature, solvent/yield ratio were studied. The optimized processing conditions obtained are extraction temperature of 78℃, isopropyl alcohol concentration of 95% (wt%), duration time of 45min, solvent/yield ratio of 1 and extraction stage number of 7.