〔Abstract〕 Objective To discuss the application of the improved food exchange system in patients with gestational diabetes mellitus. Methods 80 patients with gestational diabetes mellitus entering Shanwei People's Hospital from July 2019 to August 2021 were selected and equally divided into control group and observation group by the computer random system. The control group received traditional food exchange system for intervention,and the observation group received modified food exchange system for intervention, and the clinical intervention effects of the two groups were compared. Results There was no significant difference in fasting blood glucose, 2h postprandial blood glucose and HbA1c between the two groups before intervention (P > 0.05). After intervention, fasting blood glucose, 2h postprandial blood glucose and HbA1c in the observation group were lower than those in the control group, the differences were statistically significant (P < 0.05). There was no significant difference in triglyceride (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C) between the two groups before intervention (P > 0.05). After intervention, TG, TC and LDL-C in the observation group were lower than those in the control group, while HDL-C was higher than that in the control group, the differences were statistically significant (P < 0.05). The incidence of adverse pregnancy outcomes in the observation group was 2.50%, lower than 15.00% in the control group, and the difference was statistically significant (P < 0.05). The incidence of cesarean section in the observation group was 27.50% lower than 70.00 % in the control group, the difference was statistically significant (P < 0.05). Conclusion In patients with gestational diabetes mellitus, the improved food exchange system can effectively control the patients’ blood glucose level and blood lipid level, reduce the incidence of cesarean section, and improve the pregnancy outcome.