In the feed additive industry, plant essential oil products are mainly used to optimize the microbial balance of the digestive tract of poultry and livestock, so as to reduce inflammation, control sterilization, and guarantee the intestinal health. It is also a way of improving the quality of livestock products by increasing the feed intake of poultry and livestock, promoting their nutrient absorption, reducing the feed ratio, and enhancing their immunity. In addition, plant essential oils have great potentiality in application through playing a unique role in the digestive system, immune system, respiratory system, and reproductive system. Agricultural research has found that plant essential oils have excellent fumigation, killing and repellent effects on pests and diseases, in an advantages of naturtalness and no sequelae.