Objective To discuss the feasibility to reduce the dose of radiation in CT examination of upper airway by CT current modulation technique. Methods 60 patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) admitted in our hospital from March 2014 and February 2015 were selected as study object, which were randomly divided into three groups, 20 patients in each group, all the patients underwent upper airway CT examination. Conventional Group: tube current of 250mA, Doseright group: tube current used recommended dose from selection system, Z-DOM group: Tube current automatically adjusted in the Z-axis direction of the human body, the tube current were constant in the former groups, the tube current were changed with the scan in Z-DOM group, calculated noise ratio (CNR), the median sagittal image quality used 5 points methods for evaluation (DLP), CT dose index (CTDI) and subjective evaluation index were analyzed statistically. Results There were statistically significant differences in radiation dose among the three groups (P＜0.05), doseright group 15% higher than the conventional group, the Z-DOM group was 20% of the doseright group, 25% of the conventional group, the CNR values of the three groups were not statistically significant (P＞0.05). Subjective evaluation of the difference was statistically significant (P ＜0.05),comparison by two pairs, there was no statistically significant difference between the conventional group and the doseright group (P＜0.05),compared with the other two groups, the Z-DOM group was statistically significant. Conclusion The Z-DOM technology in the upper airway CT examination, can significantly reduce the radiation dose.