1. Distillation method: High-quality essential oils need to be distilled and filtered several times to obtain high-purity essential oils.

2. Solvent extraction method: This method has poor purity and is currently rarely used.

3. Oil separation and extraction method: used to extract flowers, the essential oil obtained is the purest, most abundant and most expensive.

4. Refrigeration compression method: The oil and water are separated using a refrigeration compression centrifuge, but distillation is still required to obtain purer essential oil.

5. Pressing method: The water and oil in the plant are squeezed out together, and then the essential oil is obtained through filtration.