To observe the effect of Baihe Gujin decoction in relieving the toxicity of lung cancer radiotherapy. Methods: Fifty-six cases of non small cell lung cancer admitted in our hospital from March 2013 to February 2016 were randomly divided into the treatment group (radiation therapy combined with traditional Chinese medicine therapy) and control group (radiation therapy), with 28 patients in each. To observe the incidence of radiation pneumonia and radiation esophagitis. Results: After treatment, over 2 degree radiation pneumonitis occurred as: 2 cases in the treatment group and 8 cases in the control group; over 2 degree radiation esophagitis occurred as: 9 cases in the treatment group and 18 cases in the control group; over 2 degree bone marrow suppression occurred as: 12 cases in the treatment group and 21 cases in the control group. The incidence of adverse reactions of the treatment group was significantly lower than that of the control group, and the difference was statistically significant (P<0.05). Conclusion: Traditional Chinese medicine Beihe Gujin decoction can significantly reduce the occurrence of radiation pneumonitis, radiation esophagitis and bone marrow suppression, improve the clinical symptoms, quality of life of patients. It is worthy of further study and clinical application.