Abstract：Objective：To observe the clinical effect of Yiqi Huatan Jiedu tang combined with gefitinib tablets for advanced non- small cell lung cancer(NSCLC) with epidermal growth factor receptor(EGFR) mutation of qi deficiency and phlegm toxin type. Methods：A total of 102 cases of patients with advanced NSCLC with EGFR mutation of qi deficiency and phlegm toxin type were divided into the control group and the observation group according to the random number table method ， with 51 cases in each group. The control group was treated with gefitinib tablets，and the observation group was treated with Yiqi Huatan Jiedu tang combined with gefitinib tablets. Before and after treatment， CD4+ ， CD8+ ， CD4+/CD8+ ， natural killer cells(NK) and Chinese medicine syndrome scores were compared between the two groups. Clinical effects and adverse reactions were compared between the two groups. Results：After treatment，CD4+，CD4+/CD8+，and NK in the two groups were increased when compared with those before treatment(P＜0.05)， and CD8 + and Chinese medicine syndrome scores were decreased(P＜0.05). After treatment，CD4+，CD4+/CD8+，and NK in the observation group were higher than those in the control group(P＜0.05)，and CD8+ and Chinese medicine syndrome score were lower(P＜0.05). After treatment，the total improvement rate was 74.51% in the observation group， higher than that of 62.75% in the control group(P＜0.05). The incidence of adverse reactions in the observation group was lower than that in the control group(P＜0.05). Conclusion：Yiqi Huatan Jiedu tang combined with gefitinib tablets can improve immune function and clinical symptoms of patients with NSCLC with EGFR mutation of qi deficiency and phlegm toxin type. It has a significant curative effect and can reduce incidence of adverse reactions.