With high incidence，malignant tumor is among the leading causes of death worldwide，and more people suffer and die form lung cancer than other types of cancer.Different therapies are used for the diverse subtypes of lung cancer，such as non-small cell lung cancer，small cell lung cancer，and large cell lung cancer.In clinical practice，there are limited therapies in modern medicine for them，and drug development lags behind，resulting in mistreatment and no proper treatment.Thus，it is urgent to find more traditional Chinese medicine(TCM) therapies and prevention strategies.TCM has unique advantage in the prevention and treatment of tumors.Professor Hua Baojin at Guang'anmen Hospital of China Academy of Chinese Medical Sciences learned the traditional tumor theory and the academic thoughts of reinforcing healthy qi and consolidating root of Yu Guiqing，Duan Fengwu，and Piao Bingkui，analyzed changing trend of first-line therapies for malignant tumors，and combined the development of TCM tumor theory to propose the theory of regulating qi and detoxifying for the TCM prevention and treatment of malignant tumors.This article described the connotation and clinical application of the theory of regulating qi and detoxifying and analyzed the ideas and methods for the treatment of lung cancer with this theory based on the medical record of clinical case.Thereby，this study is expected to promote the application of TCM to tumors and the use of this theory.