The nine kinds of compound essential oils were prepared from L-linalool, lavender essential oil, ylang ylang oil and cedar oil by means of orthogonal test. By using method of gray correlation degree, the formulations of the nine kinds of compound essential oils were studied. The optimum formula of volume ratio was L-linalool : lavender essential oil : ylang ylang oil : cedar oil =5 : 3 : 1 : 1. The selected compound essential oil is arom...