The invention discloses a multi-layer coating type essential oil organic acid compound feed additive and a preparation method and application thereof. The additive comprises core particles including plant essential oil and organic acid, a middle coating layer including casings and organic acid and a gastric bypass coating layer from interior to exterior. By means of the multi-layer coating technology, plant essential oil and organic acid are combined, the novel coating type feed additive is obtained through the reasonable ratio, the additive can effectively pass through gastric acid and is slowly released in an animal intestinal tract, and therefore effective ingredients of the product can reach the animal intestinal tracts, the physiological and immunity effects are achieved, meanwhile, aserum biochemistry index can be improved, the body immune organ index is increased, the pH value of the content of the gastrointestinal tract is lowered, growth of harmful microbes is controlled, thebalance of the intestinal tract microorganism flora is kept, the small intestinal tract form is improved, the piglet intestinal tract mucous membrane permeability is improved, the intestinal mucosa barrier is protected, and the utilization rate of nutrient substances is increased, so that the animal body growth is promoted, and the production performance is improved.