The timing medicine of traditional Chinese medicine(TCM)is based on the view of"the correspondence between heaven and man",guided by the theory of meridian flow and the principle of"treatment according to time".It selects the optimal time for treatment according to the changes of the rhythm of qi,blood,Yin and Yang in the body.Similarly,circadian rhythm is a biological phenomenon that is expressed periodically and rhythmically in organisms to adapt the alternation of day and night.The coincidence of the two lies in the induction of the time rhythm of the disease.The disorder of the biological clock is one of the important cause of the onset of lung cancer patients.TCM has a positive effect to reduce toxicity and enhance efficiency by adjusting the rhythm of the biological clock through the best treatment time point.Therefore,this paper will discuss the understanding of lung cancer in TCM,explore the relationship between lung cancer and circadian rhythm,and explore the timing treatment of lung cancer according to the theory of TCM,and provide a new idea for clinical treatment of lung cancer.