Objective To observe the changes of Betatrophin levels in type 2 diabetes mellitus combined with metabolism-related fatty liver diseases, and explore its predictive value for the disease. Methods A total of 58 patients with T2DM were admitted to the Department of Endocrinology and Metabolism in The Second Affiliated Hospital of Bengbu Medical College from January 2021 to November 2021 were selected as the case group. According to whether they had combined metabolic related fatty liver disease, patients were divided into T2DM with MAFLD group and T2DM alone group. Healthy subjects were selected as control group. We compared the general data, serum Betatrophin, blood glucose and lipid profiles, and analyzed the association between Betatrophin and type 2 diabetes mellitus with metabolic related fatty liver disease. Results There were significant differences in BMI, ALT, FPG, HOMA-IR, HbA1c, TG, LDL-C, HDL-C, Betatrophin between case group and control group (P<0.05). There were significant differences in BMI, HOMA-IR, HbA1c, TG and Betatrophin between T2DM with MAFLD group and T2DM alone group (P<0.05). Correlation analysis found that Betatrophin was positively correlated with TG. Multivariate analysis identified Betatrophin with TG as an independent risk factor for combined metabolic related fatty liver disease in patients with type 2 diabetes (P<0.05). Conclusion Betatrophin levels are significantly increased in the serum of T2DM patients with MAFLD, which promotes disease initiation and progression, and has predictive value for MAFLD.