Objective To investigate the application of head-and-neck CT angiography using a low tube voltage and low concentrations of contrast agent compared with normal dose and high concentration of contrast agent with 320-row volume CT. Methods Sixty adult patients were collected underwent the head and neck CT angiography. The patients were randomly assigned to group A (120 kV, 370 mgI/mL), B (100 kV, 370 mgI/mL), and C (80 kV, 300 mgI/mL). All three groups adopted automatic tube current regulation technology and iterative reconstruction algorithm. Then the image quality, radiation dose and iodine intake were compared among the three groups. Results The degree of enhancement in group C was higher than group A and B with significant difference; The image noise in group C was higher than A and B with significant difference; The difference of background noise, SNR and CNR among the three groups was not statistically significan; The difference of the score evaluated from the images was not statistically significant between subjective and objective method in all the three groups. Conclusion Through technical optimization and reasonable parameter selection, 320-slice volume CT using "double low" technology can be applied to the head and neck CTA examination without affecting the image quality, and effectively reduce the radiation dose.