Objective: To investigate the effects of growth hormone combined with letrozole treatment on serum sex hormone-binding globulin (SHBG), Th1/Th2 cytokines, and C1q tumor necrosis factor-related protein 9 (CTRP9) in patients with polycystic ovary syndrome (PCOS).Methods: A total of 192 patients with PCOS were included in the study and divided into a control group and a combined group according to different treatment schemes, with 96 cases in each group. The control group was treated with letrozole, while the combined group received growth hormone in addition to letrozole. The maximum follicle diameter, endometrial thickness, ovarian volume, interleukin-4 (IL-4), interferon-gamma (IFN-γ), Th1/Th2 cytokine ratios, SHBG, CTRP9, estradiol (E2), follicle-stimulating hormone (FSH), luteinizing hormone (LH), progesterone (P), pregnancy outcomes, and the incidence of adverse reactions were recorded and compared between the two groups.Results: After treatment, the combined group showed significantly higher levels of maximum follicle diameter and endometrial thickness compared to the control group (P0.05).Conclusion: The use of growth hormone combined with letrozole in the treatment of polycystic ovary syndrome can regulate immune imbalance by shifting cytokine status, enhance ovarian reserve function, and improve levels of SHBG, CTRP9, and sex hormones. This combination therapy helps improve ovulation and pregnancy rates in patients and demonstrates a good safety profile.