Objective To investigate the feasibility of low-dose CT (LDCT) imaging combined with iterative reconstruction technique for lung cancer early detection in healthy physical examination. Methods A total of 600 cases of healthy subjects were randomly divided into routine dose CT group and LDCT group, and the routine dose CT group was scanned with 120 kV and 150 mAs, LDCT group was scanned with 120 kV and 30 mAs. The LDCT scan image was reconstructed using iterative reconstruction techniques. The subjective image quality, objective image quality parameters (noise, CT value, SNR), radiation dose parameters (CTDIvol, DLP, ED) and lung nodule detection rate were compared between the two groups. Results The subjective image quality of the two groups of mediastinal window and lung window could meet the diagnostic requirements, the difference between the two groups was not statistically significant (P>0.05). The image noise of LDCT group was slightly higher than that of routine dose CT group, the difference was statistically significant (P<0.05), but the CT value and SNR between the two groups was not statistically significant (P>0.05). The CTDIvol, DLP and ED of LDCT group were significantly lower than those of routine dose CT group (P <0.01). The detection rate of lung nodules and early lung cancer in the two groups was not statistically significant (P>0.05). Conclusion LDCT combined with iterative reconstruction technique could obtain better image quality, and decrease X-ray radiation dose. It had important clinical potential for the early detection of lung cancer.