The incidence of generalized anxiety disorder (GAD) has recently been increasing year by year,in a complex social environment. The diagnosis of GAD currently often relies on DSM-5 and ICD-10 criteria, which include subjectivity and limitations. Understanding the intrinsic activity of brain network functions and structural connectivity is an important goal of contemporary neuroscience research. Electroencephalographic microstates are capable of observing broad frequency components and capturing dynamic changes in brain activity, thus providing a novel perspective on the accuracy of GAD diagnosis. This review considers the electroencephalographic microstate features and explores the abnormalities in the functional brain network in patients with GAD, with the aim of providing a clear diagnosis, optimizing the therapeutic efficacy, and improving the quality of medical care for patients with GAD.