The packaging of dairy products must have barrier properties, such as oxygen resistance, light resistance, moisture resistance, fragrance retention, odor prevention, etc… Ensure that external bacteria, dust, gases, light, water and other foreign objects cannot enter the packaging bag, and also ensure that the water, oil, aromatic components, etc. contained in dairy products do not penetrate outward; At the same time, packaging should have stability, and the packaging itself should not have odors, components should not decompose or migrate, and it must also be able to withstand the requirements of high temperature sterilization and low temperature storage, and maintain stability under high and low temperature conditions without affecting the properties of dairy products.