Abstract: Objective: To investigate the application value of HDCT low-dose dual phase scanning measurement of lung volume in patients with coal workers pneumoconiosis. Methods: Totally 30 cases of male patients with coal workers pneumoconiosis underwent low-dose chest examination with HDCT at inspiratory and expiratory phase, image reconstruction using adaptive statistical iterative reconstruction(ASIR), and all patients underwent pulmonary function tests(PFT) within 3 days after the CT scanning. The control group from the usual male patients who underwent routine dose with 64 rows of VCT chest scanning about 30 cases. Each the noise of the image and each scan volume CT dose index(CTDI, DLP, ED) was converted. The subjective image quality score between the two groups to compare the nonparametric Mann-Whitney U test. With paired samples t test to compare different scan dose and breathing state between the two groups of image noise, the volumetric CT dose index. The Pearson correlation analysis inspection throughout the lung volume index(Vin, Vex, Vin-Vex, Vex/Vin, Vin-Vex/Vin100%) and PFT index(FVC, FEV1, FEV1/FVC%). Results: All the subjective image quality evaluation in middle rating above, the image noise between two groups of the scanned without statistical significance; The sam of radiation dose of low-dose scan using ASIR technology dual phase scanning with HDCT lower than the routine dose in a single scan with VCT. Correlation was found between the lung volume index(Vin, Vex, Vex/Vin, Vin-Vex/Vin 100%) and PFT index(FVC, FEV1, FEV1/FVC%) in Coal workers pneumoconiosis patients. The Vex, Vex/Vin had a better correlation with PFT index(P<0.01). Conclusion: HDCT low-dose dual phase scanning of lung volume index can be used for assessment of lung function in patients with coal workers pneumoconiosis, and its clinical application value is high.