Abstract: Objective To investigate the clinical efficacy and safety of vitamin AD drops combined with iron proteinsuccinylate in the prevention and treatment of mild to moderate anemia in premature infants. Methods Eighty premature infants with anemia who were admitted to Hangzhou Obstetrics and Gynecology Hospital from January 2023 to June 2024 were enrolled. They were divided into a mild anemia group and a moderate anemia group according to the severity of anemia, with 40 infants in each group. All infants were treated with a combination of vitamin AD drops and iron proteinsuccinylate. The clinical efficacy, anemia-related indicators hemoglobin (Hb), serum iron (SI), serum ferritin (SF), reticulocyte count (Rtc), liver and kidney function indicators alanine amino-transferase (ALT), aspartate transferase (AST), creatinine (Cr), blood urea nitrogen (BUN) before and after treatment were observed and compared between the groups. Results The total effective rate in the mild anemia group was significantly higher than that in the moderate anemia group (P < 0.05). After 4 weeks of treatment, the levels of Hb, SI, SF and Rtc in both groups were significantly higher than baseline (P < 0.05). Moreover, the above indicators in the mild anemia group were higher than those in the moderate anemia group (P < 0.05). After 4 weeks of treatment, there were no statistically significant differences in the levels of ALT, AST, Cr and BUN compared with baseline in either group (P > 0.05). Conclusion The combination of vitamin AD drops and iron proteinsuccinylate is more effective in the treatment of premature infants with mild anemia. It can effectively improve the anemia status of premature infants with mild to moderate anemia, and has a favorable safety profile without obvious damage to liver and kidney function.