Objective To investigate the effect of Bacillus Licheniformis Capsule on dysbiosis of intestinal flora caused by GP chemotherapy for inoperable non-small cell lung cancer (NSCLC). Methods 98 cases of patients who had dysbiosis of intestinal flora caused by GP chemotherapy for inoperable NSCLC and were treated in our hospital from May 2013 to October 2016 were enrolled in the study. By the random number table method, they were divided into the control group and the study group, 49 cases in each group. The control group were treated with routine drugs, and the study group were treated with Bacillus Licheniformis Capsule. The intestinal flora, clinical efficacy, quality of life ［Karnofsky Performance Status (KPS) score］, adverse reactions and follow-up survival rate in the two groups were observed after treatment. Results There were no significant differences in Lactobacillus, Bifidobacterium, Enterobacteriaceae, Enterococcus and KPS between the two groups before treatment. After treatment, Lactobacillus, Bifidobacterium and KPS scores increased significantly, and Enterobacteriaceae and Enterococcus decreased significantly in the two groups, and the changes were more obvious in the study group than in the control group. After treatment, the total effective rate of treatment in the study group was significantly higher than that in the control group (85.71% vs 67.35%), and there was no significant difference in the total incidence of adverse reactions between the two groups. The survival rate of the study group was significantly higher than that of the control group in 6 months of follow-up. Conclusion The application of Bacillus Licheniformis Capsule in the treatment of dysbiosis of intestinal flora caused by GP chemotherapy for inoperable NSCLC can effectively regulate the intestinal flora, and improve clinical efficacy, quality of life and survival, with certain safety.