Objective To analyze the relationship between a body shape index (ABSI) and newly-diagnosed type 2 diabetes mellitus(T2DM) complicated with non-alcoholic fatty liver disease(NAFLD). Methods A retrospective study included 107 newly-diagnosed T2DM patients complicated with NAFLD treated in Affiliated Hospital of Jiangsu University. According to the results of abdominal color ultrasonography, those patients were divided into the experimental group (n=57) with T2DM complicated with NAFLD patients and T2DM group (n=50) with signal newly-diagnosed T2DM patients. Additionally, 48 healthy controls were selected into the control group (n=48). The clinical baseline data including height, weight, waist circumference(WC), and hip circumference(HC) were recorded for all participants to calculate ABSI, waist hip rate(WHR), body mass index(BMI), waist height rate(WHtR). And, the relevant biochemical indicators were measured. All the clinical parameters were compared among three groups. The relationship between ABSI and metabolic indexes was analyzed. Results Compared with T2DM group and control group, the levels of ABSI, fasting insulin, HOMA-IR, low-density lipoprotein cholesterin(LDL-C), triacylglycerol(TG), total cholesterol(TC), uric acid(UA), white blood cell(WBC), neutrophils/lymphocytes ratio(NLR), WC, WHR, BMI, and WHtR in experimental group were higher, while the level of high-density lipoprotein cholesterin (HDL-C) was lower. Furthermore, with the increase of ABSI level, the levels of fasting blood-glucose(FBG), 2-hour post-meal blood glucose(2 hPG), LDL-C, TG, TC, HOMA-IR, and NLR were remarkably elevated, which had a positive correlation. However, the level of HDL-C was decreased, which meant a negative correlation. The logistic regression analysis showed that ABSI was a risk factor for the newly-diagnosed T2DM complicated with NAFLD. The ROC curve indicated that ABSI had a certain value in predicting the NAFLD development in newly-diagnosed T2DM patients. The area under the ROC curve was 0.78. Conclusion The ABSI which has a close relation to insulin resistance and NLR level can be significantly increased and serve as a risk factor in patients with newly-diagnosed T2DM complicated with NAFLD. And it can provide a new clinical idea for the prevention and early screening of NAFLD.