ObjectiveTo investigate the clinical characteristics of non-tuberculous mycobacterium (NTM) pulmonary disease and pulmonary tuberculosis, as well as the bacterial distribution of NTM pulmonary disease. Methods The bacterial distribution and clinical characteristics of 104 patients with NTM lung disease hospitalized in Jiangxi Provincial People’s Hospital from May 2017 to May 2020 were retrospectively analyzed, as well as the clinicplal characteristics of 155 patients with tuberculosis hospitalized during the same period. Results The age of NTM lung disease group [(60±15) years] was higher than that of tuberculosis group [(55±19) years]. There were statistically significant differences in basic diseases (such as malignant tumor, type 2 diabetes, old tuberculosis, bronchiectasis), laboratory examination (such as blood routine examination, albumin) and chest imaging characteristics between the two groups (P<0.05). There was no significant difference in clinical symptoms (such as cough, sputum or fever) (P>0.05). The common underlying diseases of NTM lung disease were malignant tumor (29%), bronchiectasis (21%), chronic obstructive pulmonary disease (19%), etc. The common clinical symptoms of NTM lung disease included cough, sputum, fever, hemoptysis, chest tightness and shortness of breath, and other non-specific respiratory symptoms. The common manifestations of NTM lung disease on chest high-resolution CT (HRCT) included patchy images (82%), mediastinal lymph node enalargement (35%), pleural thickening (31%), pleural effusion (26%) and other signs. The isolates of NTM included Mycobacterium avium (50%), Mycobacterium intracellulare (21%), Mycobacterium chelonae/abscessus (14%), Mycobacterium fortuitum (5%), Mycobacterium gordonae (4%), Mycobacterium gilvum (3%), and Mycobacterium smegmatis (3%). Multivariate Logistic regression analysis showed that advanced age (OR=1.027) was a risk factor for NTM lung disease. Conclusions The clinical manifestations of NTM lung disease and tuberculosis are similar and difficult to distinguish. For male patients over 60 years old with malignant tumor, old tuberculosis, bronchiectasis and other basic diseases, and the chest HRCT findings are mainly bronchiectasis, NTM lung disease should be actively excluded. There is little difference in clinical manifestations between different strains of NTM lung disease, and the treatment cycle of NTM lung disease is long and easy to be interrupted, requiring enhanced follow-up.