Weight-adjusted Waist Index (WWI) is a novel tool for evaluating human metabolism. By standardizing waist circumference with body weight, it compensates for the limitations of traditional Body Mass Index (BMI). It performs remarkably well in predicting health risks, including type 2 diabetes mellitus (T2DM), cardiovascular diseases, and metabolic syndrome. This paper summarizes the research progress of WWI in T2DM and its complications. It is found that WWI can effectively predict the onset of diabetes and various complications, with superior assessment efficacy compared with conventional indicators, and combined indexes possess higher predictive value. At present, WWI has not been widely applied clinically, and its diagnostic criteria and action mechanism remain to be further explored. After relevant research is improved, WWI is expected to serve as an effective assessment method for diabetes risk screening and complication early warning.