Objective To investigate abnormal patterns of functional connectivity（ FC） in the amygdala among patients with chronic insomnia disorder（ CID） and their specific relationship with anxiety symptoms using resting-state functional magnetic resonance imaging（ rs-fMRI）. Methods This study adopted a crosssectional design， selecting 32 CID patients who visited the outpatient department of the First Affiliated Hospital of Hainan Medical University between December 2020 and December 2022 to form the insomnia group. During the same period， 32 age- and gender-matched healthy individuals were recruited to form the control group. All participants underwent rs-fMRI scans. The Pittsburgh Sleep Quality Index（ PSQI）， Hamilton Anxiety Scale（ HAMA）， Insomnia Severity Index（ ISI） and Beck Depression Inventory II（ BDI-Ⅱ） were used to assess the sleep quality， anxiety， severity of insomnia and depressive disorder. A whole-brain FC analysis method using the bilateral amygdalae as seed points was used to compare FC differences between the two groups and to further analyze the correlation between abnormal FC and scale scores. Results The PSQI， ISI， HAMA， and BDI- Ⅱ scores in insomnia group were all higher than those in control group， with statistically significant differences（ t/Z=23.032、-6.896、21.911、4.039； all P＜0.001）. Compared with control group， insomnia group exhibited statistically enhanced FC in the bilateral amygdala and multiple regions of the left parietal cortex （including the angular gyrus and supramarginal gyrus）（ P ＜ 0.05， FDR-corrected）. Analysis of FC revealed that this enhancement shifted from a negative correlation in control group to a positive correlation in insomnia group： left amygdala-left angular gyrus［ control group：（ -0.11±0.14） vs. insomnia group：（ 0.03±0.14）， t=4.050， P ＜ 0.001， Cohen's d=1.01］， right amygdala-left angular gyrus/left supramarginal gyrus［ control group：（ -0.14±0.15） vs. insomnia group：（ 0.03±0.16）， t=4.361， P ＜ 0.001， Cohen's d=1.09］， right amygdala-right supramarginal gyrus［ control group：（ -0.12±0.14） vs. insomnia group：（ 0.04±0.15）， t=4.473， P＜ 0.001， Cohen's d=1.12］. Correlational analysis revealed that in insomnia group， FC of left amygdala and left angular gyrus was statistically positively correlated with HAMA scores（ r=0.412， P=0.019）， whereas it showed no statistically significant correlation with the severity of insomnia（ PSQI and ISI scores）（ P ＞ 0.05）. Conclusions CID patients exhibit a FC pattern transition from physiological antagonism to pathological synergy between the amygdala and key nodes of the default mode network and the attention network（ angular gyrus and supramarginal gyrus）. This abnormal neural circuit reorganization may specifically underlie the neurobiological basis of anxiety symptoms in patients with CID， and holds promise as a potential imaging biomarker for assessing anxiety levels and guiding precision interventions.