Disclosed are multiple pharmaceutical usages of a small-molecule hyaluronic acid fragment, comprising: treating tumors, conjunctival diseases, xerophthalmia, vitreous opacitees, myofascitis, arthrolithiasis, cardiovascular diseases, cerebral infarction, dysmenorrhea, endometriosis, periodontal diseases, herpes zoster, burns, pains, pruritus, acute pancreatitis, and postoperative abdominal adhesions, helping with body recovery after chemotherapy and facial cosmesis, reducing subcutaneous fat and the like. Also disclosed are an injectable of the small-molecule hyaluronic acid fragment and a preparation method for the injectable. The small-molecule hyaluronic acid fragment is injected into a subcutaneous fat layer of the abdomen for facial cosmesis and anti-aging.