Objective To explore the anti-cancer function of old drugs from the perspective of the concept of Chinese herbal nature combination, and provide method and a new thinking style for the new function discovery from old drugs under the guidance of the theory of traditional Chinese medicine (TCM). Methods Using lung cancer with qi and yin deficiency as the example, the therapeutic principles of TCM anti-lung cancer treatment were analyzed and Chinese herbal nature combination patterns (CHNCP) for cancer treatment were extracted based on the relationship between function and Chinese herbal nature combination. The chemical medicines were re-screened with the cancer CHNCP and the candidates were identified. Results The therapeutic principle of TCM anti-lung cancer treatment is invigorating qi and nourishing yin. Fifteen chemical medicines were identified as the anti-cancer candidates, including 2 anti-cancer drugs being used in clinics and 4 drugs having the anti-cancer activity. Conclusion The method for finding the anti-cancer function of old drugs based on the Chinese herbal nature combination is feasiable, which provide new clues for application of old drugs.