Objective: To explore the correlation between the attenuation index (FAI), plaque quantification parameters and white matter hyperintensities (WMH). Methods: Clinical, coronary computed tomography angiography and brain magnetic resonance imaging data of 407 consecutive patients were retrospectively collected between January 2021 and December 2022. According to the Fazekas scale (0-6), our study cohort was divided into mild WMH group (Fazekas score 0-2) and moderate to severe WMH group (Fazekas score 3-6). Clinical data, FAI, and plaque quantification parameters were compared between two groups, and independent variables associated with moderate to severe WMH were identified. Results: Significant differences were found on FAI and plaque quantification parameters between two groups (P<0.05). Age (OR=1.116, 95%CI: 1.074-1.160, P<0.001), coronary artery disease (OR=2.737, 95%CI: 1.270-6.017, P=0.010), plaque burden (OR=4.142, 95%CI: 1.228-13.977, P=0.022), and FAI > -70.1 HU (OR= 5.089, 95%CI: 1.899-13.640, P=0.001) were found to be independently associated with moderate to severe WMH. Conclusions: Age, coronary artery disease, plaque burden, and FAI>-70.1HU are independent factors associated with moderate to severe WMH. Our study provides a theoretical basis for the co-management of coronary atherosclerosis and WMH.