Objective: To investigate the accuracy and clinical utility of dual-source CT virtual non-contrast (VNC) imaging in the differential diagnosis between aneurysmal rupture with acute subarachnoid hemorrhage (SAH) and aneurysmal wall calcification (AWC) in the acute phase. Methods: A prospective study was conducted, including 100 patients with acute SAH in our hospital between September 2022 and July 2025. These patients underwent conventional non-contrast (TNC) and dual-energy CTA scans, and VNC images were generated through post-processing. Using surgical/follow-up results as the gold standard, we compared the detection rate, area, and CT value differences between TNC and VNC for hemorrhagic and calcified lesions. The sensitivity, specificity, and Kappa consistency of the two techniques were calculated. Results: The detection rate of hemorrhagic lesions in TNC was 80.00%, while that in VNC was 88.00%, with a statistically significant difference (P < 0.05). VNC showed a greater involvement of cisterns and a larger maximum area compared to TNC, with statistically significant differences (P < 0.05). There were no statistically significant differences in the detection rate and maximum thickness of AWC between the two techniques (P > 0.05). The CT value of calcified lesions in VNC was lower than that in TNC, with a statistically significant difference (P < 0.05). There was no difference in CT value between TNC and VNC for calcified lesions (P < 0.05). The area under the curve (AUC) for distinguishing hemorrhage from calcification in VNC was 0.953 (95% CI 0.912–0.994), which was higher than that in TNC (0.887, 95% CI 0.815–0.958) (P＜0.05). The optimal cutoff value for VNC was 73 HU (sensitivity 96.3%, specificity 89.7%); the CTDIvol and DLP levels in VNC were lower than those in TNC, with statistically significant differences (P < 0.05). In terms of image quality, VNC scored higher than TNC in anatomical structure display, lesion boundary clarity, degree of artifacts, and overall satisfaction, with statistically significant differences (P < 0.05). Conclusion: Dual-source CT-VNC can accurately differentiate between acute bleeding and calcification in ruptured aneurysms through a single dual-energy CTA examination without additional scanning, reducing patient radiation dose and possessing significant clinical application value.