Abstract: Objective: To analyze the value of the clinical application of a dual-low protocol in which 60 kV low tube voltage and low-concentration contrast medium are combined with the artificial intelligence iterative reconstruction (AIIR) algorithm, in lower extremity computed tomography angiography (CTA). Methods: Eighty patients undergoing lower extremity CTA were enrolled, and they were assigned 1︰1 to a control group or an experimental group, according to the scanning protocol. Patients in the control group were scanned at 80 kV with KARL 3D iterative reconstruction and 0.8 ml/kg iohexol, and patients in the experimental group received 60 kV with AIIR reconstruction and a 6︰4 diluted contrast agent (equivalent to 0.6 mL/kg of iohexol). All examinations were performed using a United Imaging uCT Sirius dual-source CT scanner with a reference mAs of 162; the other parameters were identical. Subjective image quality was assessed by two radiologists in a double-blinded manner. Parameters, including vascular CT attenuation, image noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), radiation dose, and iodine intake, were measured and compared between the groups. Results: There were no significant differences in baseline data, subjective image scores, or image noise between the two groups, and the image quality of both groups met the clinical diagnostic criteria. The CT attenuation value, SNR, and CNR of each vascular segment were significantly higher in the experimental group than in the control group. Compared with the control group, the CT Dose Index, Dose Length Product, effective dose, and iodine intake of the experimental group were reduced by 82.8%, 79.1%, 77.8%, and 25.3%, respectively. Conclusion: The application of 60 kV tube voltage and low-concentration contrast agent combined with the AIIR algorithm in lower extremity CTA can optimize vascular imaging quality, while ensuring diagnostic image quality. This significantly reduces the radiation dose and iodine intake, making it suitable for clinical application.