Evaluated with the yield of anise star oil, steam extraction method assisted by microwave is studied for the extraction of anise star oil from Illicium verum Hook. f. in contrast with the traditional steam distillation (SD) method in this paper. The new optimal steam extraction technology assisted by microwave of anise star oil is obtained as: extracting time 80 minutes, solid-liquid ratio(g/mL) 1:7, size of material 80~100 mesh and extracting temperature 80°C. Average yield of anise star oil is up to 11.6% (g/g) under the above technology. Size of material is the most important influencing factor in the extraction process. The optimal traditional steam distillation technology is: extracting time 120 minutes, solid-liquid ratio(g/mL) 1:6, size of material 80~100 mesh and extracting temperature 100°C , the average yield of anise star oil is only 9.81% (g/g). The steam extraction technology assisted by microwave has advantages in both the technological conditions and the yield of anise star oil than the traditional steam distillation technology.