Disclosed are a hyaluronic acid-based amphiphilic polymer, preparation method and application thereof. A main chain of the amphiphilic polymer is a hydrophilic hyaluronic acid and can be employed in active targeting, and a side chain thereof is a hydrophobic group represented by Formula (1). The amphiphilic polymer can carry a small molecule anticancer drug. Polymer nanoparticles are obtained via chemical crosslinking, such that the nanoparticles are not readily dissociated outside a cell or in blood, thus ensuring the stability of a drug encapsulated by the nanoparticles. Upon arriving at a tumor tissue, the hyaluronic acid on a surface of the nanoparticle can immediately combine with a CD44 receptor on a surface of a tumor cell, and effectively enter the tumor cell via endocytosis mediated by the receptor, and then quickly de-crosslink to be dissociated. The drug is quickly released, obtaining an enrichment ratio at a tumor site markedly higher than that of the prior art, resulting in a highly effective treatment, and addressing deficiencies such as drug leakage, low carrying efficiency, low occurrence of endocytosis and slow release in a cell.
