<p>As short video use has become a highly prevalent phenomenon in daily life, growing concern has emerged regarding its excessive use, which has been associated with impaired attention, cognitive dysfunction, and adverse mental health outcomes, while its relationship with intrinsic large-scale brain network dynamics remains unclear. This study investigated whether excessive short video use is associated with altered resting-state EEG microstate dynamics. A total of 154 participants were classified into an excessive use group (EU, <i>n</i> = 86) and a moderate use group (MU, <i>n</i> = 68) using a short video addiction questionnaire. Resting-state EEG was recorded under an eyes-closed condition, and four canonical microstates (A–D) were identified. Duration, frequency, time coverage, and transition probabilities were analyzed using mixed-design ANOVAs. Compared with the MU group, the EU group showed greater frequency and time coverage of microstate C, lower frequency and time coverage of microstate D, and increased transitions toward microstate C but decreased transitions involving microstate D. No significant differences were found for duration or for microstates A and B. Supplementary SVM analysis further showed moderate discrimination between groups, with a mean nested cross-validation accuracy of 82.4% and a hold-out test accuracy of 71.0%. These findings suggest a selective reorganization of resting-state brain dynamics in excessive short video users, which may have adverse implications for cognitive-emotional functioning, particularly in attentional regulation and executive control.</p>