Potassium sorbate is mainly used as food preservative, cosmetics preservative and feed mould proof. It has a strong inhibition of spoilage bacteria and mold, and is easily soluble in water, so it is widely used. The lower the pH value, the stronger the antibacterial effect. Sorbic acid (potassium) can effectively inhibit the activities of molds, yeasts and aerobic bacteria, and also prevent the growth and reproduction of harmful microorganisms such as botulinum, Staphylococcus and Salmonella. However, it has almost no effect on beneficial microorganisms such as anaerobic bacillus and Lactobacillus acidophilus. Its inhibitory effect on development is stronger than bactericidal effect, so as to effectively prolong the storage time of food, And keep the original food flavor.