We compared the effect of varying iodine contrast medium (CM) dosage on image quality and radiation dose in low-tube voltage dual source computed tomography (DSCT) pulmonary artery imaging was compared by sinogram affirmed iterative reconstruction (SAFIRE) combined with non linear blending (NLB), and optimization of pulmonary artery imaging protocol. A total of 166 patients were divided into groups A, B, C, and D based on the amount of CM used and tube voltage. The voltage of group A tube was 120kV, and CM dosage was 50ml, filtered back projection combined with linear blending post-treatment technology was adopted, In contrast, the voltage of group B, C and D tubes was 80kV/Sn140kV, the dosage of CM was 20ml, 30ml, 50ml, respectively, and SAFIRE combined with NLB was adopted. The CT values were highest in group D and lowest in group A, with groups C and D exhibiting values significantly greater than those in groups A and B (P<0.05). The background noise of groups A and B were significantly higher than groups C and D (P<0.05). contrast to noise ratio and signal to noise ratio of pulmonary arteries at all levels in group C and D were higher than those in group A and group B (P<0.05). pulmonary arteries and their branches in the groups A, B, C and D showed well, and the pulmonary artery emboli could be clearly displayed, with good inter observer consistency. The CT dose index volume, dose length product, and effective dose of group A were significantly higher than those of groups B, C, and D (P<0.05). This application of SAFIRE combined with NLB in DSCT enhances image quality while concurrently reducing contrast medium (iodine) dosage and radiation exposure.