〔Abstract〕 Objective To observe the effect of Bailing capsule combined with chemotherapy on the immune function of patients with advanced lung cancer. Methods 80 patients with stage Ⅲ ~ Ⅳ non-small cell lung cancer admitted to the First People's Hospital of Shangqiu from January 2020 to August 2021 were selected and divided into an observation group and a control group by random number table method, with 40 cases in each group. The control group was given chemotherapy alone, and the observation group was additionally given Chinese medicine Baling capsule on the basis of the control group. Both groups were treated for 4 cycles. The percentage of CD3+ CD4+ T, CD3+ CD8+ T, CD56+ CD16+ (NK), CD8+ CD28+ T, CD8+ CD28- T and CD4+ CD25+ CD127lowT cells and the ratio of CD4/CD8 were detected by flow cytometry. Results Before treatment, there was no statistical significance in the percentage of CD3+ CD4+ T, CD3+ CD8+ T, NK, CD8+ CD28+ T, CD8+ CD28- T, CD4+ CD25+ CD127lowT and CD4/CD8 ratio in peripheral blood of the two groups (P > 0.05). After treatment, the levels of CD3+ CD4+T、NK and CD8+ CD28+ T cells in the two groups were significantly increased compared with before treatment, and the levels of CD3+ CD4+ T, NK and CD8+ CD28+ T cells in the observation group were higher than those in the control group, the differences were statistically significant (P < 0.05). The levels of CD3+ CD8+ T and CD8+ CD28- T cells in the two groups showed a downward trend after treatment, but the difference was not statistically significant (P > 0.05). CD4/CD8 ratio of the two groups showed an upward trend after treatment, but the difference was not statistically significant (P > 0.05). The levels of CD4+ CD25+ CD127lowT cells in the observation group decreased significantly after treatment compared with before treatment, the differences were statistically significant (P < 0.05), while there was no significant difference in the levels of CD4+ CD25+ CD127lowT cells in the control group before and after treatment (P > 0.05). The incidence of adverse reactions in the observation group was lower than that of the control group, and the difference was statistically significant (P < 0.05). Conclusion Bailing capsules combined with chemotherapy can improve the immune function of patients with advanced lung cancer, and play a role in increasing efficiency and reducing toxicity.