In recent years, the incidence of generalized anxiety disorder (GAD) is at an increasing stage year by year in a complex social environment. Currently, the diagnosis of GAD often relies on DSM-5 and ICD-10 criteria, which have certain subjectivity and limitations. Understanding the intrinsic activity of brain network function and structural connectivity has proven to be an important goal of contemporary neuroscience research. EEG microstates are capable of observing broad frequency components and capturing dynamic changes in brain activity as a way to provide a new way of thinking about the accuracy of GAD diagnosis. This paper delves into the EEG microstate features and explores the abnormalities in the functional brain network of GAD patients, aiming to further provide a clear diagnosis, optimize the therapeutic efficacy and improve the quality of medical care for GAD patients.