This study is a 24-week, single-center, randomized, double-blind, sham-controlled, parallel-group clinical trial. A total of 38 patients with type 2 diabetes and mild cognitive impairment were enrolled and randomly assigned in a 1:1 ratio to either the treatment group (receiving active transcutaneous auricular vagus nerve stimulation) or the sham control group (receiving sham transcutaneous auricular vagus nerve stimulation). The primary objective of this study is to evaluate the potential disease-modifying effects of transcutaneous auricular vagus nerve stimulation on cognitive impairment in patients with type 2 diabetes.