The invention provides whitening compound essential oil and a preparation method thereof. The whitening compound essential oil is prepared from the following components in parts by mass: 5-20 parts of lavender essential oil, 0.5-5 parts of orange flower essential oil, 0.2-2 parts of rose essential oil, 0.5-5 parts of cananga odorata essential oil, 0.1-1.2 part of 40% glabridin, 0.5-2.5 parts of stearyl glycyrrhetinate, 1-8 parts of squalane and 70-90 parts of base oil. On one hand, the whitening compound essential oil is completely prepared from pure natural essential oil and pure natural plant extract, and most essential oil is a small molecular substance and has good permeability; the speed of absorbing the essential oil by a human body is very rapid, so that whitening factors rapidly reach deep layers of cells under the guidance and action of the essential oil, and a melanin generating enzyme is found and locked and the activity is inhibited, so that a melanin generating capability of skin cells is rapidly reduced, and skins are obviously whitened within short time; the whitening compound essential oil is safe and has no irritation and no toxic side effect so that the whitening compound essential oil is suitable for being used for a long period; and on the other hand, the glabridin and the squalane as well as the stearyl glycyrrhetinate which is a whitening, sun-protection and freckle-removing component are added according to a certain ratio, thus having a synergistic effect, and further enhancing the whitening effect.