Principle: Supercritical CO2 Fluid Extraction(SCFE) technology is the latest subject of modern chemical separation technology, and it is an advanced separation process emerging in the world at present. Supercritical extraction means that under certain pressure and appropriate temperature, in the extraction cylinder, the solvent is in full contact with the extracted substance, the solute diffuses into the solvent, and then the working conditions are changed in the separator, so that the dissolved substances are separated out to achieve the purpose of separation. The critical temperature of CO2 is 31℃ and the critical pressure is=7.4MPa. It is higher than the critical state, its density is close to liquid, its viscosity is close to gas, and its diffusion coefficient is 100 times that of liquid, so it has extremely strong solubility.