Objective: To analyze the application effect of arginin recombinant human insulin combined with menthyl insulin in gestational diabetes mellitus. Methods: 100 cases of gestational diabetes mellitus patients in our hospital were selected from January 2023 to January 2025, and randomly divided into observation group and control group, 50 cases in each group. Menthol insulin was used in the control group, and arginine protein recombinant human insulin was added in the observation group. The two groups were compared in terms of therapeutic efficacy, fasting blood glucose (FPG), 2hPG, glycosylated hemoglobin (HbA1c), insulin resistance index (HOMA-IR), HOMA-β, FINS, homocysteine (Hcy), cystatin C (CysC), TNF-α, IL-6, CRP levels, and adverse reactions. Results: The treatment efficiency of 46 patients in the observation group was higher than that of 36 patients in the control group (P < 0.05); after medication, the levels of FPG, 2hPG, HbA1c, HOMA-IR, Hcy, CysC, TNF-α, IL-6, and CRP in the observation group were lower than that of the control group, and the levels of HOMA-β and FINS were higher than that of the control group (P < 0.05); the comparison of the adverse reactions between the two groups showed no significant difference (P＞0.05). Conclusion: Sperm protein recombinant human insulin combined with menthyl insulin is effective in the treatment of gestational diabetes mellitus, which can reduce blood glucose level, improve pancreatic islet function, regulate serum indexes, reduce inflammatory symptoms, and has better safety.