Background Neuropsychiatric symptoms (NPSs) are exhibited in most patients with Alzheimer’s disease (AD), especially the delusional symptoms are commonly seen. Previous studies suggest that vascular changes such as white matter hyperintensities (WMH) have a significant association with specific NPS.The current study comparing the WMH volume in delusional and non-delusional Alzheimer's to explore the relationship between WMH and delusional symptoms in AD patients. Methods In total,80 AD patients divided into delusional group (n = 36) and non-delusional group (n = 44) according to the Neuropsychiatric Inventory(NPI) scale.The WMH volume of these 80 patients was quantitatively calculated.Include the whole Brain WMH volume, Periventricular WMH(PVWMH) volume, Deep WMH volume, bilateral frontal WMH volume, bilateral temporal WMH volume, bilateral parietal WMH volume and bilateral occipital WMH volume. Firstily,Compared the WMH volume between the delusional group and the non-delusional group.Sencondly,The delusional patients were divided into mild, moderate and severe groups according to the NPI. We Compared the different severity of delusional group to explore the role of WMH volume in delusional symptoms. Results There was a significant difference in WMH volume in the left occipital lobe (P < 0.05).In the delusional group, there were significant differences in the total volume of WMH and PVWMH volume (P < 0.05).Posthoc test showed that WMH volume were significantly different between mild and severe delusional symptoms (P < 0.05). Conclusion Left occipital WMH volume may affect the development of delusional symptoms.In AD patients, WMH promote the serious of delusional symptoms.