Serum 1,5-anhydroglucitol (1,5-AG) levels can not only accurately reflect the mean blood glucose over the previous 1-2 weeks in diabetic patients but also offers the advantage of representing postprandial glucose. To evaluate the clinical significance of 1,5-AG in diabetes detection, especially when used in combination with fasting plasma glucose (FPG), a total of 3098 participants at high risk for diabetes (1467 men, 1631 women) were enrolled. A total of 1471 (47.5%) participants were diagnosed with diabetes, and the mean 1,5-AG level in the diabetic group was significantly lower than that in non-diabetic group [12.5 (7.8-17.5) μg/mL vs. 20.5 (15.3-26.4) μg/mL, P < 0.001]. The optimal cut-off point was 15.9 μg/mL, for which the sensitivity, specificity, and area under the curve (AUC) were 69.2%, 72.3%, and 0.781, respectively. For the combination of FPG and 1,5-AG, the sensitivity, specificity, and AUC improved to 82.5%, 83.5%, and 0.912, respectively. This method helped 75.8% of the participants avoid an oral glucose tolerance test (OGTT), reducing the need to carry out the OGTT by 43.9% compared to the use of the FPG criterion only. In conclusion, the addition of FPG to serum 1,5-AG improves the efficiency of diabetes screening in the Chinese population.