Objective To explore the effects of continuous theta-burst stimulation（ cTBS） applied to the right dorsolateral prefrontal cortex（ DLPFC） on local spontaneous brain activity in patients with depressive disorder， and to analyze its potential neuroimaging mechanisms based on fractional amplitude of low-frequency fluctuation（ fALFF）. Methods This study was a randomized， double-blind， sham-controlled clinical trial. A total of 59 patients with depressive disorder who completed treatment between April 2023 and March 2024 at Beijing Anding Hospital， Capital Medical University and passed imaging quality control were selected as study subjects and randomly assigned to the real-stimulus group（ n=31） and the sham-stimulus group（ n=28）. The realstimulus group received individualized cTBS targeting the right DLPFC， while the sham-stimulus group received matched sham stimulation intervention， with a treatment duration of 10 days for both groups. All participants completed the 17-item Hamilton Depression Scale（ HAMD-17） assessments and resting-state functional magnetic resonance imaging（ fMRI） scans before treatment and within three days after treatment. Whole-brain voxel-level fALFF analysis was performed， and a 2（ group： real-stimulus group/sham-stimulus group） × 2（ time： pre-test/ post-test） repeated-measures analysis of variance was conducted to test for a group × time interaction effect. Results The HAMD-17 score reduction rate was higher in the real-stimulus group than in the sham-stimulus group［ （60.10±20.80）% vs.（ 20.30±27.10）%］， and the difference was statistically significant（ t=6.360， P＜0.001）. Whole-brain analysis revealed a group × time interaction effect（ peak coordinates： -2，-58，44； 80 voxels） in the bilateral precuneus（ cluster-level PFWE=0.001）. Post-hoc analysis showed that fALFF values in the precuneus of the real-stimulus group increased from（ 1.47±0.40） to（ 1.69±0.42）， while those in the shamstimulus group decreased from（ 1.82±0.40） to（ 1.43±0.42）. An analysis of the correlation between changes in fALFF values and clinical efficacy showed that there was no statistically significant correlation in either the realstimulus group or the sham-stimulus group（ both P ＞ 0.05）. Network localization analysis indicated that this brain region was primarily located in the paracingulate network（ 55/80 voxels） of the executive control subnetwork and partially overlapped with the core region of the default mode network. Conclusions cTBS applied to the right DLPFC enhances local spontaneous brain functional activity in the precuneus of the paracingulate network in patients with depressive disorder， suggesting that altered local activity in posterior medial cortical regions such as the precuneus may be one of the potential neuroimaging mechanisms underlying the antidepressant effects of cTBS.