Abstract: Objective: To analyze the value of coronary CT angiography (CCTA) using dual-source CT with Turbo-Flash mode to evaluate coronary artery stenosis. Methods: A total of 150 patients who underwent CCTA in hospital between January 2023 and December 2024 were selected and divided into an observation group (dual-source CT with Turbo-Flash mode, n=75) and control group (retrospective electrocardiographic-gating mode, n=75) according to the scan mode used. The scan parameters CT-derived fractional flow reserve (CT-FFR), intraluminal contrast density, Agatston scores for calcification, and calcification volume, image quality CT value and signal-to-noise ratio (SNR), and radiation doses dose length product (DLP), volume CT dose index (CTDIvol), and ED of the two groups were analyzed. Results: CT-FFR, intraluminal contrast density, and Agatston score for calcification were greater in the observation group than in the control group (P<0.05). Under dual-source CT with Turbo-Flash mode, as the degree of coronary artery stenosis increased, the CT-FFR, intraluminal contrast density, and Agatston score for calcification increased (P<0.05). Taking DSA as the gold standard, the diagnostic sensitivity, specificity, and accuracy for moderate-severe coronary artery stenosis in the observation group were 96.43%, 87.23%, and 90.67%, respectively. No statistically significant difference was observed compared with the control group (P<0.05). The differences in CT values, SNR, and image quality between the two groups were not statistically significant (P>0.05). DLP, CTDIvol, and ED were lower in the observation group than in the control group (P<0.05). Conclusion: Dual-source CT with Turbo-Flash mode for CCTA can achieve high accuracy and image quality when evaluating coronary artery stenosis. The degree of stenosis can be evaluated through quantitative parameters. Moreover, the DLP, CTDIvol, and ED are relatively low. These findings are worthy of clinical promotion and application.