Abstract: Objective To explore the clinical efficacy of linezolid in the treatment of pulmonary tuberculosis complicated with severe pneumonia and effects on immune factors and prognosis. Methods From January 2016 to January 2017, 98 patients with pulmonary tuberculosis complicated with severe pneumonia were randomly divided into the control group (49cases) and the observation group (49 cases). On the basis of anti-tuberculosis treatment, the two groups were treated with imipenem cilastatin and imipenem cilastatin combined with linezolid, respectively, both groups were followed up for28 days. The clinical efficacy, bacterial clearance rate, immune function, cytokine levels, prognosis and incidence of adverse reactions were compared between the two groups after treatment. Results The total effective rate of the observation group was significantly higher than that of the control group (89.80% vs. 73.47%, P=0.037), and the bacterial clearance rate of the observation group was significantly higher than that of the control group (79.59% vs. 57.14%, P=0.017). The levels of CD4⁺, CD8⁺, CD4⁺/CD8⁺, Ig A and Ig G in the two groups were significantly higher than those before the treatment (all P < 0.05), and the above indexes in the observation group were higher than those in the control group (all P < 0.05). The levels of IL-6, IL-8 and TNF-α in the two groups were significantly lower than those before the treatment (P < 0.05), and the above indexes in the observation group were significantly lower than those in the control group (all P < 0.001). The survival rate of the observation group was significantly higher than that of the control group (HR=0.360, 95% CI:0.153-0.849, P=0.027); There was no significant difference in the incidence of adverse reactions after treatment between the two groups (12.24% vs. 10.20%, P=0.749). Conclusion Linazolamide can improve clinical efficacy, enhance immune function, reduce serum cytokine levels and improve the survival rate of patients in the treatment of pulmonary tuberculosis with severe pneumonia, and the safety is guaranteed.