Objective: To explore the application effect of dietary nutrition management combined with quantitative exercise intervention in prenatal management of Gestational Diabetes Mellitus (GDM) patients. Methods: 92 GDM patients admitted to the obstetrics department of our hospital from January 2022 to January 2024 were selected as the study objects. The control group received routine prenatal management, the observation group received dietary nutrition management combined with quantitative exercise intervention. Blood glucose control (HBA1c, fasting blood glucose, 2 h postprandial blood glucose), nutritional level (albumin, prealbumin) and weight gain during pregnancy were analyzed and compared between the two groups. Results: After intervention, the levels of HBA1c, fasting blood glucose and 2h postprandial blood glucose in both groups were significantly lower than before intervention, and the levels of HBA1c, fasting blood glucose and 2h postprandial blood glucose in the observation group were significantly lower than those in the control group (P < 0.05). After the intervention, the levels of albumin and prealbumin in both groups were significantly higher than before the intervention, and the levels of albumin and prealbumin in the observation group were significantly higher than those in the control group (P < 0.05). The weight gain and the proportion of rapid weight gain in the observation group were significantly lower than those in the control group (P < 0.05). Conclusion: Prenatal management combined with dietary nutrition management and quantitative exercise in GDM patients can control the blood glucose level and weight gain during pregnancy, and improve the nutritional level of patients.