Objective To explore the application of multi-slice spiral CT (MSCT) in the diagnosis of pulmonary ground-glass opacity (GGO). Methods The clinical data and MSCT imaging data of 58 cases of GGO patients confirmed by CT-guided biopsy or surgical pathology in our hospital from August 2016 to September 2017 were retrospectively analyzed. The differences between benign lesions, atypical adenomatous hyperplasia (AAH) and malignant lesions were compared and analyzed. Results Among the 58 cases of GGO, there were 23 cases of simple GGO (12 benign cases, 6 AAH cases and 5 malignant cases) and 35 cases of mixed GGO (5 benign cases, 30 malignant cases). The age and lesion size of benign GGO, AAH and malignant GGO were that benign GGO age<aahbenign GGO>AAH (P>0.05). There were significant differences in the MSCT imaging features (lesion shape, boundary definition, marginal morphology and lesion bronchoalveolar inflated sign, pleural indentation and vessel convergence sign) among the benign GGO, AAH and malignant GGO (P>0.05). Conclusion GGO contains a variety of diseases, and different types of GGO have different performance of MSCT signs, and MSCT has high diagnostic values for the benign or malignant GGO, therefore it is worthy of further referral.