Hyaluronic acid is the main proteoglycan widely distributed in the extracellular matrix of soft connective tissues. It has good biocompatibility and biodegradability and has a wide range of applications in clinical medicine. In the field of medicine, hyaluronic acid and its derivatives As an excellent drug carrier, it can achieve the purpose of drug thickening, sustained drug release, and promotion of drug penetration and targeting. Hyaluronic acid, as a medium for ophthalmic preparations, can significantly improve drug bioavailability and has moisturizing properties. Lubricating, anti-inflammatory and promoting repair effects; as a drug slow-release carrier, it can delay the release rate of drugs, and it also has a bioadhesive effect on some biological macromolecule drugs; as a targeted carrier of anti-tumor drugs, it can increase the presence of anti-tumor drugs in tumors. And the absorption and retention time in the lymph nodes, improve the efficacy of the drug.