Mainly divided into three

1. Steam distillation method: It is the most widely used method at present. It has simple equipment, easy operation and low cost. However, due to the relatively high operating temperature, it will cause the decomposition and hydrolysis of heat-sensitive substances in the essential oil, and the extracted essential oil will be decomposed and hydrolyzed. The moisture contained in it must be removed first. The steps are more complicated.

2. Solvent extraction method: Organic solvent extraction uses volatile organic solvents to extract components from plant raw materials. The resulting products are extracts, tinctures and the like. Organic solvent extraction may cause solvent residues, and the extraction time is too long and the efficiency is relatively low.

3. Pressing method: Crushing and pressing the raw materials, extruding the volatile oil from the plant tissue, then standing for stratification and separating the oil with a centrifuge. The essential oil obtained by this method is of good quality and can maintain the original fragrance. Essential oils used in food and cosmetics are mostly obtained by cold pressing.