Objective To investigate the effects of enteral nutrition on inflammatory factors, cancer⁃induced fatigue and quality of life in patients with advanced lung cancer complicated with pneumonia. Methods A total of 124 patients with advanced lung cancer complicated with pneumonia admitted to Cancer Hospital of Huanxing Chaoyang District Beijing from May 2019 to March 2020 were selected as the research object, and the patients were divided into observation group and control group on average according to the lottery method.The control group was fed ordinary food, and the observation group was supplemented with enteral nutritional support. Inflammatory factors, cancer⁃induced fatigue and quality of life were observed in 2 groups. Results There were no significant differences in procalcitonin, C⁃reactive protein, interleukin⁃6, tumor necrosis factor ⁃α and α⁃1 acidic glycoprotein between 2 groups before treatment (t=0.161, 0.134, 0.692, ⁃0.412, 0.226, P=0.436, 0.446, 0.245, 0.340, 0.410). After 2 weeks of treatment, the levels of interleukin⁃6, tumor necrosis factor ⁃α and α⁃1 acid glycoprotein in the observation group were significantly higher than those in the control group (t =3.566, 9.833, 3.951, P < 0.01).After treatment, the fatigue score in the observation group was (22.07±3.45) points, significantly lower than that in the control group (31.12±3.13) points; after treatment, the scores of physical fatigue (9.93±4.31), emotional fatigue (6.11±2.36), cognitive fatigue (6.03±3.22) and the scores of physical fatigue (12.25±3.77), emotional fatigue (9.84±2.79) and cognitive fatigue (9.03±1.98) in the observation group were compared with those in the control group points were statistically significant (P < 0.01).Before treatment, there was no significant difference in quality of life score between the observation group and the control group (P > 0.05). The total score of quality of life in observation group was (191.22±5.39) points, which was significantly higher than that in control group (150.88±6.27) points. The scores of the observation group were (48.17±10.62), mental function (58.24±2.39), social function (46.55±2.16), material life (38.36±4.88) and the control group were (40.95±12.31). The scores of psychological function, social function and material life were (41.45±1.77) points, (37.24±3.79) points and (31.24±5.13) points respectively (P < 0.05). Conclusion In the treatment of patients with advanced lung cancer complicated with pneumonia, enteral nutrition agents can effectively improve the therapeutic effect of lung infection, significantly reduce fatigue caused by cancer and improve the quality of life, which has important clinical significance.