Objective To compare the value of Modified Early Warning Score (MEWS) and MEWS combined with blood glucose score in the evaluation of prognosis in patients with acute diabetic complications. Methods An analysis was conducted in 419 patients with acute complications of diabetes in the Endocrinology Department of Pingdingshan the Second People's Hospital. All the patients were evaluated with MEWS and MEWS combined with blood glucose score and divided into survival group and death group from admission to discharge. The prediction accuracy in patients' prognosis of MEWS and MEWS combined with blood glucose score were compared between the two groups. Results The score of MEWS and MEWS combined with blood glucose score of the death group were (4.43±1.39) and (8.32±7.41) respectively, while those of the survival group were (2.77±2.41) and (4.11±7.26) respectively. The differences were statistically significant (t=-3.338, -2.755; P<0.01). Using death as the predictor, the area under the receiver operating characteristic curve (AUC) of MEWS was 0.875 (95%CI: 0.840-0.905), with medium resolution, and the optimal cut-off value was more than 4; Youden index was 0.640 3, the sensitivity was 78.43%; specificity was 85.60%; the positive predictive value was 43.01%, and the negative predictive value was 96.63%. The AUC of MEWS combined with blood glucose score was 0.982 (95%CI: 0.964-0.992), with high resolution, and the optimal cut-off value was more than 7; Youden index was 0.897 7; the sensitivity was 94.12%; the specificity was 95.65%;the positive predictive value was 75.00%, the negative predictive value was 99.15%. Conclusions MEWS combined with blood glucose score can better predict diabetes outcomes in patients with acute complications, and it is worthy of clinical application.