Objectives: To explore the clinical characteristics of NTM-PD and provide scientific basis for the diagnosis and treatment. Methods: Clinical characteristics, laboratory tests, chest CT, bacterial strain identification, drug sensitivity, and treatment outcome of 170 NTM-PD patients diagnosed in our hospital from Jan. 2018 to Dec. 2019 were analysed, and compared with clinical data of 300 pulmonary tuberculosis (PTB) patients diagnosed in the same period. Results: The proportion of chest tightness, asthma, haemoptysis, tuberculosis history and complications in NTM-PD group was higher than that in PTB group (P<0.05). The positive rate of T-SPOT in PTB group was significantly higher than that in NTM-PD group (P <0.05). The percentages of CD4+ molecules and CD4+/CD8+ in the NTM-PD group were lower than those in the PTB group (P<0.05). In the NTM-PD group, IFN-γand IL-2 were lower than those in the PTB group, and IL-4 and IL-10 were higher than those in the PTB group (P<0.05). CT findings of the two groups showed statistically significant differences in cavitation, bronchiectasis, pneumothorax and lung damage (P<0.05). The drug resistance rate of NTM-PD patients to the anti-tuberculosis drugs is as high as over 90%, while the drug resistance rate of ethambutol is slightly lower than 40.6%. Six kinds of NTM were found in 131 patients in the NTM-PD group, among which mycobacterium intracellular was found to account for 69.8% at most, Mycobacterium tortoise abscess subspecies accounted for 9.2%, others were Mycobacterium avium(7.3%), Mycobacterium Kansas (5.5%), sporadic Mycobacterium (5.5%), and Mycobacterium Gordon (1.8%). Only 39 cases (23%) of NTM-PD patients had significant absorption after long course of disease, difficult treatment and intensive treatment for 2 months, and most patients relapsed within 6 months. Conclusions: Chest tightness, haemoptysis, tuberculosis history, complications, blood T-SPOT, pulmonary cavitation, bronchiectasis, pneumothorax, lung damage have reference value for the diagnosis of NTM-PD. NTM-PD patients have limited drug selection, long course of treatment, easy to relapse, and poor prognosis of the elderly.