Sodium acetylated hyaluronate (AcHA) is obtained by acetylation reaction of natural moisturizing factor sodium hyaluronate (HA). The introduction of acetyl group enables AcHA to have both hydrophilic and lipophilic properties, and can exert dual moisturizing, repairing the stratum corneum barrier, improving skin elasticity and other biological activities, thereby improving dry and rough skin and making the skin soft and elastic.