The present invention provides a method and system for separating linalyl acetate from Lavender essential oil and preparing its derivatives, whereby the supercritical fluid technology is used to feed Lavender essential oil and supercritical solvent into the first separating tank, where linalyl acetate and linalool are separated from Lavender essential oil; then linalyl acetate is conveyed to the second separating tank, where linalyl acetate is separated with wax-containing oily substance to obtain high-concentration linalyl acetate; next linalool and vitamin C solution are conveyed to a reaction tank for esterification synthesis, and the reaction tank is filled with acid resin catalyst to obtain linalool-vitamin C derivative; with this design, it is possible to reduce the nervous tension, and adjust high-concentration linalyl acetate affecting physiological and psychological stress, as well as vitamin C derivative with anti-oxidizing oily fragrance.