Compound essential oil is a combination of different types of essential oils with different effects, including cinnamal dehyde, thymol, carvacrol, and eugenol.It is a new technology product acting on the main pathogenic bacteria of digestive tract and respiratory tract of livestock and poultry, developed by the advanced multi-layer envelop technology,and includes the selection of natural plant essential oil for food, the screening of bacteriostatic effect, multiple compound compatibility tests and the determination of biomarker gene, etc. essential oil can effectively inhibit the growth of various pathogens, and easily enhance mucosal immune function through intestinal mucosa, and significantly promote the expression of intestinal aquaporin gene (AQP8) and defensin gene (pBD-1), which is highly effective in improving animal disease and diarrhea resistance.